Nanofunctionalized polymer carrier having titanium dioxide-based photocatalytic nanoparticles and its use as a photocatalyst

Abstract

The present invention relates to a support nano-functionalized with photocatalytic nanoparticles. The support is preferably an article of manufacture. The support is preferably made of a transparent or translucent polymeric material and is characterized by a nano-roughness between 10 and 150 nm, as measured by electron microscopy, and a macro-roughness between 100 and 600 μm, as measured by electron microscopy, the nano- and macro-roughness being internally and / or superficially diffused. The present invention also relates to a method for preparing the nano-functionalized support of the present invention. The present invention further relates to the use of the nano-functionalized support as a photocatalyst activated by ultraviolet and / or visible light for the decontamination of fluids, preferably air and / or water, from organic pollutants, bacteria, mold, odors, and combinations thereof. Finally, the present invention also relates to a filtration device comprising at least one nano-functionalized support of the present invention, associated with at least one source of ultraviolet and / or visible light configured to irradiate the at least one nano-functionalized support.

Description

[Technical Field]

[0001] The present invention relates to a polymer carrier nanofunctionalized with photocatalytic nanoparticles and a method for producing the same. The carrier is suitable for treating contaminated gases or liquid fluids by photocatalytic decomposition of contaminants present in the contaminated gas or liquid fluid, and is activated by ultraviolet light, visible light and / or sunlight. [Background technology]

[0002] The use of light energy in the photodegradation process of chemical substances, such as reducing pollutants in the liquid or gas phases, is currently one of the most interesting research areas, both from a scientific and technological standpoint and from the perspective of resource investment by developed industrial nations. The use of titanium dioxide (TiO2) is advantageous because it is reasonably priced, readily available, non-toxic, chemically and thermally stable, and possesses high oxidizing power, particularly for nitrogen oxides (NO, NO). x Titanium dioxide (TiO2) photocatalysts play a fundamental role in this field due to their numerous advantages, including their effectiveness against pollutants such as UV rays, NO2, and volatile organic compounds (VOCs). Furthermore, a further advantage is the modification of TiO2, which allows for enhanced photocatalytic effects not only in the ultraviolet spectrum (as in the case of TiO2 photocatalysts) but also in the sunlight spectrum. Thus, visible radiation from both sunlight and indoor lighting lamps can be utilized, thereby overcoming the high costs and problems associated with the use of UV lamps, such as the generation of O3. Modification of TiO2 is generally achieved by introducing oxygen vacancies or by doping with transition metals (Cu, Ni, Co, Mn, Fe, Cr, Mo, V, and W, etc.), noble metals (Au, Ag, and Pt, etc.), rare earth elements, and more recently, nonmetals (e.g., C, N, P, S, F, etc.). In particular, nitrogen doping has been shown to be one of the most effective methods for improving the activity of TiO2 in the visible light spectrum.

[0003] Nanofunctionalized supports made from ceramic materials (e.g., cordierite, mullite, or alumina), or other types of materials coated with photocatalytic coatings of TiO2 or TiO2 nanoparticles doped with various doping agents, are known at the current level of technology.

[0004] In the paper "Surface characterization and photocatalytic performance of N-doped TiO2 thin films deposited onto 200 pore size alumina membranes by sol-gel methods" by R. Grilli et al., Materials Chemistry and Physics, vol. 159, 2015, pp. 25-37, a sol-gel method developed for depositing nitrogen-doped TiO2 thin films used for water treatment and filtration through a porous Al2O3 membrane with photocatalytic activity in the visible spectrum and pore size of 200 nm, is described. Meanwhile, the paper WO2010 / 151231 discloses a composite material containing nitrogen-doped TiO2 and activated carbon (AC). For example, as described in the applicant's patent application WO2018 / 207107, a nanofunctionalized ceramic support having a honeycomb structure, active in both the ultraviolet and visible spectra, and comprising a nitrogen-doped TiO2 photocatalytic nanoparticle coating, is manufactured by a method requiring the application of an aqueous suspension of titanium oxide nanoparticles containing a nitrogen-containing doping agent to the support and the carrying out a heating (firing) cycle of the support at a temperature between 490 and 510°C. Ceramics, being inert and highly resistant materials, are widely used in this field today, given that they ensure the long lifespan of the equipment in which they are used; however, this type of support has many drawbacks. In fact, the use of ceramic supports has considerable technical limitations, particularly related to the hardness and brittleness of the support itself, the lack of flexibility of the finished product, the application of production methods with high energy consumption associated with high-temperature heating (firing) cycles, the limited possibility of choice for various geometric shapes, thicknesses, and forms, and the inherent opacity of the ceramic material itself, which eliminates the possibility of manufacturing transparent or translucent supports. Furthermore, it is well known that most of these drawbacks are also common to many other types of materials, such as activated carbon or the porous membranes mentioned above.In this context, the fundamental technical challenge of the present invention is to propose an optimized alternative to currently available photocatalytic carriers, which would have a higher effect and provide a versatile, miniaturizable, and customizable system from both a hydrodynamic perspective, thanks to the possibility of changing the geometric shape, thickness, and form, and from a photocatalytic perspective, thanks to the possibility of controlling the roughness and / or transparency as needed of the material. In contrast, problems exist in the current state of technology and are associated with the use of nanofunctionalized carriers made from, for example, ceramics or other materials that are brittle, hard, or have other undesirable properties. Indeed, the search for materials that not only have the potential to obtain complex geometric shapes and forms, but also preferably have a certain degree of transparency to optimize the transmission of ultraviolet or visible light and / or sunlight, and consequently optimize photocatalytic performance, is a currently very real challenge in the field of photocatalytic decomposition of pollutants in water and / or air purification applications. Reflecting these technical characteristics, among the candidate materials, plastic materials are undoubtedly one of the most versatile materials for manufacturing carriers in all kinds of shapes, thicknesses, and sizes, possessing optical properties that can range from completely opaque to completely transparent. Techniques for manufacturing this type of carrier from plastic materials, such as 3D printing, injection molding, and extrusion, are also less costly from an energy standpoint, as they do not involve high-temperature firing or further processing or synthesis steps, as is the case with carriers made from ceramic materials or other technically more complex materials (e.g., porous Al2O3 films or activated carbon composites). However, one of the main problems that remains unresolved is the adhesion of nanoparticle coatings to carriers made from polymer materials, and in particular, the identification of photocatalysts that are compatible with, can penetrate, and / or stably bond to said polymer materials to form a coating.The aforementioned technical problems are solved by the present invention, which provides a nanofunctionalized support with TiO2-based photocatalytic nanoparticles and relates to its use in a photocatalyst for decontaminating fluids from organic pollutants, wherein the support is preferably made of a transparent polymer material and is characterized by having internally and / or surfacely diffused nanoroughness and macroroughness, which allows the photocatalytic nanoparticles to adhere to the support effectively, and when irradiated with ultraviolet and / or visible light sources, the photocatalytic nanoparticles become effectively available to perform photocatalytic action. [Overview of the Initiative]

[0005] The present invention relates to a carrier that is nanofunctionalized with photocatalytic nanoparticles and activated under irradiation with ultraviolet light, visible light, and / or sunlight. In a particularly preferred embodiment, the nanofunctionalized carrier in the present invention is a nanofunctionalized product.

[0006] The carrier according to the present invention is preferably made of a transparent or translucent polymer material and is characterized by nanoroughness between 10 and 150 nm as measured by an electron microscope and macroroughness between 100 and 600 μm as measured by an electron microscope, wherein the nanoroughness and macroroughness are diffused internally and / or on the surface.

[0007] Preferably, the photocatalytic nanoparticles exist in the polymer material and / or on at least one inner surface and / or outer surface of the carrier in the present invention in the form of a nanoparticle coating. The photocatalytic nanoparticles are preferably selected from the group consisting of TiO2, transition metals, noble metals, rare earth elements, nonmetals, and TiO2 doped with elements selected from combinations thereof.

[0008] The present invention also relates to a method for preparing the nanofunctionalized carrier of the present invention, the method comprising preparing a carrier made from a polymer material by 3D printing, injection molding, or extrusion of the polymer material, and then applying a suspension of photocatalytic nanoparticles.

[0009] In one embodiment of the present invention, the polymer material may already contain photocatalytic nanoparticles, and after being prepared once by 3D printing, injection molding, or extrusion with a suspension of photocatalytic nanoparticles applied, it can optionally be further functionalized.

[0010] The present invention is further preferably NO, NO X The present invention relates to the use of nanofunctionalized carriers as photocatalysts activated by ultraviolet and / or visible light and / or sunlight for decontaminating fluids, preferably air and / or water, from organic pollutants selected from among NO2, COV, SOV, bacteria, mold, odors, and combinations thereof.

[0011] Finally, the present invention relates to a filtration device for removing contaminants from a fluid, preferably air and / or water, from the organic contaminants, the filtration device comprising at least one nanofunctionalized carrier of the present invention, associated with at least one light source configured to emit radiation in the ultraviolet and / or visible light spectrum and irradiate the at least one nanofunctionalized carrier. [Brief explanation of the drawing]

[0012] [Figure 1] This shows the particle size analysis of the powder sample (before calcination) in Example 2, performed dry using a Sympatec HELOS (H0969) laser.

[0013] [Figure 2] The DSC graph of the pre-calcination powder sample in Example 2, obtained using spray drying technology, is shown.

[0014] [Figure 3] The diffractogram of the calcined powder in Example 2 is shown.

[0015] [Figure 4]Scanning electron microscope (SEM) images of the cross-section of the nitrogen-doped TiO2 nanoparticle coating present on the nano-functionalized honeycomb ABS carrier (HC-1) obtained according to Example 3 are shown.

[0016] [Figure 4a] Two different enlarged views (digital zoom) of FIG. 4 are shown, from which the nano-roughness data of the sample could be estimated. [Figure 4b] Two different enlarged views (digital zoom) of FIG. 4 are shown, from which the nano-roughness data of the sample could be estimated.

[0017] [Figure 5] Scanning electron microscope (SEM) images of the cross-section of the nitrogen-doped TiO2 nanoparticle coating present on the nano-functionalized honeycomb ABS carrier (HC-1) obtained according to Example 3, measured at different locations of the sample, are shown.

[0018] [Figure 5a] An enlarged view (digital zoom) of FIG. 5 is shown, from which the nano-roughness data of the sample could be estimated.

[0019] [Figure 6] Scanning electron microscope (SEM) images of the cross-section obtained by freeze fracture of the nano-functionalized honeycomb ABS carrier (HC-1) obtained according to Example 3 in liquid nitrogen are shown, showing the characteristic macro-roughness highlighted by arrows (1) and (2), where the arrow indicates the distance between one protrusion and the next, which can be likened to the distance between one valley and the next.

[0020] [Figure 6a] An enlarged view (digital zoom) of FIG. 6 is shown, from which the macro-roughness data (i.e., the numerical value in μm) of the sample highlighted by the arrows (1) and (2) could be estimated.

[0021] [Figure 6b]A further enlarged view (digital zoom) of Figure 6 is shown, from which it was possible to estimate the thickness data of the nitrogen-doped TiO2 nanoparticle coating present on the nanofunctionalized honeycomb ABS support (HC-1) obtained in Example 3.

[0022] [Figure 7] A schematic diagram showing SEM images is provided, from which it was possible to estimate the coating thickness data, indicated by arrows and squares in the figure, as well as the nano-roughness (3) and macro-roughness (1) and (2) data for the nano-functionalized honeycomb ABS carrier (HC-1) obtained in Example 3.

[0023] [Figure 8] The image shows a nanofunctionalized translucent support made from ABS having a complex woven layered structure, including multiple channels and / or cells, manufactured by 3D printing, according to one embodiment of the present invention.

[0024] [Figure 9] As described in Example 5, a graph showing the trend in the reduction of contaminants (NOX) by irradiation using a 3000K LED is shown. The results obtained for the nanofunctionalized honeycomb supports (HC-1, HC-2, HC-3, and HC-4) coated with TiO2-N nanoparticles in the present invention are compared with the results obtained for the prior art ceramic honeycomb support (HC-REF) similarly coated with nitrogen-doped titanium oxide nanoparticles.

[0025] [Figure 10] The graph shows the reduction of contaminants (NO) by irradiation using a 3000K LED for the honeycomb supports nanofunctionalized with TiO2-N nanoparticle coatings in HC-5 and HC-6 of the present invention, obtained as described in Example 3 and tested as described in Example 6.

[0026] [Figure 11]The graph shows the reduction of contaminants (NO) by irradiation using a 3000K LED for the honeycomb support nanofunctionalized with TiO2-N nanoparticle coating in the present invention's HC-7 and HC-8, obtained as described in Example 3 and tested as described in Example 6.

[0027] [Figure 12] The graph shows the reduction of contaminants (NO) by irradiation using a 3000K LED for the honeycomb supports nanofunctionalized with TiO2-N nanoparticle coatings in the present invention, HC-8 and HC-9, obtained as described in Example 3 and tested as described in Example 6.

[0028] [Figure 13] The graph shows the reduction of contaminants (NO) by irradiation using a 3000K LED for the honeycomb supports nanofunctionalized with TiO2-N nanoparticle coatings in the present invention, HC-10 and HC-11, obtained as described in Example 3 and tested as described in Example 6.

[0029] [Figure 14] The graph shows the reduction of contaminants (NO) by irradiation using a 3000K LED for honeycomb supports nanofunctionalized with TiO2-N nanoparticle coatings according to the present invention, HC-10, HC-12, HC-13, and HC-14, obtained as described in Example 3 and tested as described in Example 6.

[0030] [Figure 15] As described in Example 6, a graph showing the trend in the reduction of contaminants (NO) by irradiation using a 3000K LED is shown. The results obtained for the honeycomb support nanofunctionalized by coating with TiO2-N nanoparticles in the present invention (HC-8 and HC-11) are compared with the results obtained for the prior art ceramic honeycomb support (HC-REF) similarly coated with nitrogen-doped titanium oxide nanoparticles.

[0031] [Figure 16] As described in Example 6, a graph showing the reduction of contaminants (NO) by irradiation using a 3000K LED is shown. The results obtained for the honeycomb support nanofunctionalized with TiO2-N nanoparticle coating in the present invention (HC-7 and HC-10) are compared with the results obtained for the prior art ceramic honeycomb support (HC-REF) similarly coated with nitrogen-doped titanium oxide nanoparticles.

[0032] [Figure 17] As described in Example 6, a graph showing the reduction of contaminants (NO) by irradiation using a 3000K LED is shown. The results obtained for the nanofunctionalized honeycomb support with TiO2-N nanoparticle coating in the present invention (HC-7, HC-8, HC-10, and HC-11) are compared with the results obtained for the prior art ceramic honeycomb support (HC-REF) similarly coated with nitrogen-doped titanium oxide nanoparticles.

[0033] [Figure 18] This graph shows the trend in reducing contaminants (NO, NOX, and NO2) by irradiation using a 3000K LED for a cuboidal nanofunctionalized ABS support ("SAMPLES") having a coating of TiO2-N nanoparticles with a macroroughness of less than 10 μm, as described in Example 7.

[0034] [Figure 19] This graph shows the trend in reducing contaminants (NO, NOX, and NO2) by irradiation using a 3000K LED for the nanofunctionalized ABS support ("SAMPLE-R") of the present invention, which has a rectangular parallelepiped structure coated with TiO2-N nanoparticles as described in Example 7, obtained by 3D printing, and has a macro-roughness of 270 μm. [Modes for carrying out the invention]

[0035] For the purposes of this invention, the terms “polymer material” or “plastic material” mean a wide range of synthetic or semi-synthetic organic polymer compounds having high molecular weight, which are malleable and therefore can be made into solids. The organic polymer compound may be a pure (co)polymer or a (co)polymer containing other substances, such as organic and / or inorganic additives, for the purpose of improving properties and reducing costs.

[0036] For the purposes of this invention, the term "(co)polymer" is used to refer to both polymers, also called homopolymers, i.e., polymers whose polymerization chain consists of repeating units obtained from the bonding of only one type of monomer, and copolymers, i.e., polymers whose polymerization chain consists of repeating units obtained from the bonding of two or more different types of monomers.

[0037] For the purposes of this invention, the term "transparent" means the physical property of transparency, i.e., the property that allows light to pass through the material.

[0038] In particular, for the purposes of this invention, a material that transmits light and allows for clear observation of an object through that material is defined as "transparent."

[0039] The term "translucent" refers to the physical property of being semi-transparent, which allows light to diffuse and pass through a material.

[0040] In particular, for the purposes of the present invention, a material is defined as "translucent" if it transmits light by diffusion but is not transparent, that is, if the object cannot be clearly observed through the material.

[0041] The term "opaque" refers to the physical property of a material that prevents light from passing through it.

[0042] In particular, for the purposes of this invention, a material is defined as "opaque" if it does not transmit light, that is, if it completely prevents observation of an object through the material because it does not transmit light.

[0043] The terms “suspension of nanoparticles” and “nanoparticle suspension” are considered synonymous for the purposes of the present invention and mean a mixture in which finely divided solid nanoparticles are dispersed in a solvent, such as water and / or alcohol, so as not to precipitate, or so as to be easily redispersible after possible precipitation.

[0044] The terms “nanofunctionalized carrier” or “nanofunctionalized product” mean that the carrier or product comprises photocatalytic nanoparticles. The photocatalytic nanoparticles may be present within the material or product forming the carrier, or within a nanoparticle coating covering at least one surface of the carrier or product, which is internal and / or external. The expression “internal and / or external surface of the carrier or product” means, for the purposes of the present invention, any surface of the carrier or product, whether it is visible from the outside (external surface) or, in the case of more complex geometric shapes and / or forms of the carrier or product, including cavities, channels and / or gaps, whether it is not visible from the outside (internal surface). For example, a carrier or product manufactured in the shape and geometric form of a hollow sphere has an external surface visible to the observer and an internal surface facing the internal hollow space and therefore not directly visible to the observer.

[0045] The term "macro-roughness" refers to the properties of a body surface consisting of geometric micro-defects, which may originate from the inherent properties of the material forming the body and / or from machining. Such micro-defects are measured by observation with a roughness tester or electron microscope and generally appear as depressions, valleys, or scratches of variable shape, depth, and direction, and their alternating arrangement forms protrusions or tips on the surface. The protrusions or tips may have variable shapes and / or geometric shapes. The protrusions or tips have an average size on the order of tens or hundreds of micrometers, and thus define the surface as a "macro-roughness" surface. In the case of the polymer carrier of the present invention, the macro-roughness is between 100 and 600 μm, preferably between 200 and 300 μm, i.e., the protrusions or tips have an average size between 100 and 600 μm, preferably between 200 and 300 μm (as shown by numerical references (1) and (2) in Figures 6 and 6a). "Average size of projection or tip" therefore means, for the purposes of the present invention, the average distance between a projection (or tip) and the following, which can be likened to the distance between a depression (or valley or scratch) and the following, as shown in references (1) and (2) of Figure 6, 6a or 7.

[0046] The term "nanoroughness" refers to a property, measured by electron microscopy or AFM, that relates to the presence of nanoparticles in a material and / or as a coating on the surface of the material, which "roughens" the surface on a nanometer scale, i.e., a surface exhibiting imperfection in the shape of protrusions or tips having an average size on the order of nanometers. In the case of the polymer carrier of the present invention, the nanoroughness is between 10 and 150 nm, preferably 10 and 50 nm, more preferably 20 and 40 nm, i.e., the protrusions or tips have an average size that is between 10 and 150 nm, preferably 10 and 50 nm, more preferably 20 and 40 nm, and the protrusions or tips are made of nanoparticles that appear partially or entirely from the surface or are present thereon as a coating, as shown, for example, by reference (3) in Figure 7. The term "ultraviolet light" refers to ultraviolet radiation, i.e., electromagnetic radiation having wavelengths just below visible light and just above X-rays, i.e., wavelengths between about 10 and about 380 nm.

[0047] The term "visible light" refers to visible radiation, which is the range of electromagnetic radiation with wavelengths just above ultraviolet light and just below infrared light, specifically wavelengths between approximately 380 and 720 nm.

[0048] The term "sunlight" refers to solar radiation, that is, the radiant energy emitted by the sun from interplanetary space, and includes electromagnetic radiation of various wavelengths. Specifically, about 50% of solar radiation is emitted in the infrared region (NIR, close to the visible region, between approximately 750 nm and 1500 nm), about 5% in the ultraviolet region, and the remainder in the visible region.

[0049] For the purposes of this invention, the term “fluid” means a material (i.e., a substance or mixture of substances) that deforms indefinitely (flows) when subjected to shear strain, regardless of the latter entity. The term “fluid” is therefore used to describe states of material including liquids, gaseous substances (gases), plasmas, and plastic solids.

[0050] The present invention relates to a nanofunctionalized carrier with photocatalytic nanoparticles, which is activated under irradiation with ultraviolet and / or visible light and / or sunlight. In a particularly preferred embodiment, the carrier is a manufactured product, which is preferably selected from the group consisting of furniture, design objects, and components. The carrier in the present invention is a carrier made of a polymer material characterized by nanoroughness contained between 10 and 150 nm as measured by an electron microscope and macroroughness contained between 100 and 600 μm as measured by an electron microscope, wherein the nanoroughness and macroroughness are diffused internally and / or surfacely. The nanoroughness is preferably contained between 10 and 50 nm, preferably between 20 and 40 nm. Preferably, the macroroughness is contained between 200 and 300 μm. The expression “nano / macro roughness is diffused internally and / or superficially” means that the carrier in the present invention can exhibit the nano and macro roughness in all parts thereof, i.e., at least one internal surface and / or external surface of the carrier, or in parts incorporated within the polymer material forming the carrier (in the latter case, which can be observed or measured by cutting the carrier). In other words, the carrier in the present invention is a carrier made of a polymer material characterized by nano roughness, measured by electron microscopy, which is diffused internally and / or superficially and is contained between 10 and 150 nm, preferably 10 and 50 nm, more preferably 20 and 40 nm, wherein the nano roughness derives from the presence of the photocatalytic nanoparticles contained within the polymer material and / or their presence as a coating on the surface of the carrier. In other words, the nanoroughness originates from the presence of protrusions or tips made by nanoparticles having an average size between 10 and 150 nm, preferably between 10 and 50 nm, more preferably between 20 and 40 nm, which partially or entirely appear from the surface of the carrier or are present thereon as a coating (for example, as shown by reference (3) in Figure 7), wherein the surface is preferably the inner surface and / or outer surface and / or cross-section of the carrier.In addition to the nanoroughness described above, the carrier according to the present invention is a carrier made of a polymer material, which is also characterized by macroroughness measured by an electron microscope, which is diffused internally and / or on the surface and is between 100 and 600 μm, preferably between 200 and 300 μm, and the macroroughness derives from the presence of geometric microdefects. The microdefects appear as protrusions or tips having variable shapes and / or geometric forms. The protrusions or tips have an average size between 100 and 600 μm, preferably between 200 and 300 μm, and the protrusions or tips are made up of alternating depressions, valleys or scratches, and the distance between one depression (or valley or scratch) and the next is between 100 and 600 μm, preferably between 200 and 300 μm. "Average size of projections or tips" therefore means the average distance between a projection (or tip) and the following, which can be likened to the distance between a depression (or valley or scratch) and the following, as shown in numerical references (1) and (2) in Figure 6, Figure 6a, or 7. In a particularly preferred embodiment of the present invention, the projections or tips are regularly and / or uniformly distributed on all parts of the carrier, i.e., on at least one inner surface and / or outer surface of the carrier, or on parts incorporated into the polymer material forming the carrier (in the latter case, which can be observed or measured by cutting the carrier), and the projections or tips are preferably distributed on all parts of the carrier in the form of a regular pattern.

[0051] Without wishing to be bound by any particular theory, it is possible to assume that the macroroughness is related to the processing of the polymer material and / or support. In particular, it is possible to assume that the geometric microdefects are due to the inherent properties of the polymer material and / or the processing of the support. Preferably, as will be described later in relation to the method for obtaining the support in the present invention, the processing is selected from the group consisting of 3D printing, injection molding, and extrusion techniques, followed optionally by further operations suitable for creating the desired specific macroroughness. With respect to nanoroughness, it is possible to assume that the nanoroughness is due to the functionalization of the support by photocatalytic nanoparticles, which, once in contact with the polymer material characterized by the macroroughness, become organized to create characteristic nanoroughness.

[0052] Without wishing to be bound by any particular theory, the applicant has surprisingly discovered that by combining the nanoroughness, which is between 10 and 150 nm, preferably 10 and 50 nm, more preferably 20 and 40 nm, and the macroroughness, which is between 100 and 600 μm, preferably 200 and 300 μm, as measured by electron microscopy, it is possible to obtain a nanofunctionalized support made from a polymer material in which the support has perfect compatibility between the nanofunctionalized photocatalytic nanoparticles and the polymer material itself. This compatibility is closely related to the amount of photocatalytic nanoparticles that can effectively functionalize the support, and consequently to its photocatalytic performance, as shown in the Examples section. In fact, this compatibility not only improves the fixation of photocatalytic nanoparticles to the support and allows for the effective functionalization of the support with a large amount of photocatalytic nanoparticles, but also effectively maintains adhesion to the support, thus enabling the reliable long-term maintenance of high-performance photocatalytic activity. Furthermore, specific nanoroughness and macroroughness values ​​in the support of the present invention make it possible to ensure an effective amount of photocatalytic nanoparticles present both inside the support and in the form of a nanoparticle coating on at least one inner surface and / or outer surface of the support.

[0053] In one embodiment of the present invention, the nanofunctionalized carrier is a carrier made from a polymer material, the polymer material comprising at least one (co)polymer selected from polymethyl methacrylate (PMMA), polyamide (PA), polycarbonate (PC), polylactic acid (PLA), polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile styrene acrylate (ASA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate glycol (PET-g), polyurethane (PU), polypropylene (PP), copolyester, and combinations thereof.

[0054] In preferred embodiments, the nanofunctionalized carrier is a carrier selected from acrylonitrile butadiene styrene (ABS) and polyethylene terephthalate glycol (PET-g), preferably acrylonitrile butadiene styrene (ABS). Preferably, the nanofunctionalized carrier in the present invention is opaque, translucent, or transparent. In preferred embodiments of the present invention, the nanofunctionalized carrier is translucent or transparent in order to advantageously utilize up to 100% of the incident light radiation diffused by or passing through the carrier, thereby obtaining excellent photocatalytic performance.

[0055] In a more preferred embodiment, the nanofunctionalized support is transparent. The support in the present invention is preferably a nanofunctionalized support having photocatalytic nanoparticles selected from the group consisting of TiO2, TiO2 doped with elements selected from ultraviolet and / or visible light and / or sunlight, transition metals, noble metals, rare earth elements, nonmetals, and combinations thereof. More preferably, the transition metal is selected from Cu, Ni, Co, Mn, Fe, Cr, Mo, V, W, Y, and Sc; the noble metal is selected from Au, Ag, and Pt; the rare earth element is selected from Ce, La, Pr, Nd, Te, and Yb; and the nonmetal is selected from C, N, P, S, and F. The size of the photocatalytic nanoparticles is preferably between 10 and 150 nm, preferably between 10 and 50 nm, preferably between 20 and 40 nm, and more preferably between 48 and 150 nm, and is measured as a Z-mean using DLS (Dynamic Light Scattering, Malvern Instruments) technique. For example, the range of 48 to 150 nm has a Z-mean equal to an integer or decimal number within the range of 48 to 150 nm, and the polydispersity index is less than 0.3, preferably between 0.21 and 0.29, and more preferably between 0.216 and 0.286. Such polydispersity values ​​indicate excellent uniformity in the size of the nanoparticles. Therefore, for example, if the Z-mean of the nanoparticles is equal to 49.9 and the polydispersity index is 0.221, it means that the nanoparticles are uniformly distributed in terms of size, and almost all nanoparticles have an average diameter of about 49.9 nm.

[0056] The photocatalytic activity of the nanofunctionalized support in this invention is oxidative photocatalytic activity, and under irradiation (by ultraviolet light, visible light, and / or sunlight, depending on the type of nanoparticle), the nanoparticles react with many organic substances present in air or water, such as NO. x Because it acts as a powerful oxidizing agent for VOCs (volatile organic compounds), VOS (volatile organic solvents), bacteria, mold, or odors (the latter consisting of organic matter and bacteria), it contributes to their reduction and, as a result, contributes to the purification of air and / or water.

[0057] In a particularly preferred embodiment of the present invention, the carrier is a carrier functionalized with photocatalytic nanoparticles active in both ultraviolet and visible light (and consequently sunlight), more preferably nitrogen-doped TiO2 nanoparticles (TiO2-N). Preferably, the TiO2-N nanoparticles are present in the polymer material of the carrier and / or on at least one inner surface and / or outer surface of the carrier in the form of a nanoparticle coating.

[0058] The amount of doping nitrogen present in the TiO2-N nanoparticles is between 1 and 5% by weight, preferably between 1.5 and 3% by weight, relative to the total weight of the nanoparticles.

[0059] In a more preferred embodiment, the TiO2-N nanoparticles have at least one brookite crystalline phase in an amount of 10 to 99% by weight relative to the weight of the nanoparticles, as determined by X-ray diffraction analysis. Preferably, the TiO2-N nanoparticles further have a rutile crystalline phase. More preferably, the TiO2-N nanoparticles having at least one brookite crystalline phase and a rutile crystalline phase also have an anatase crystalline phase. In one embodiment, the TiO2-N nanoparticles have a brookite crystalline phase in an amount of 90 to 99% by weight relative to the weight of the nanoparticles, and the remaining amount of rutile and / or anatase crystalline phase up to 100%. In one embodiment, the TiO2-N nanoparticles have at least two crystalline phases of TiO2, namely a brookite crystalline phase in an amount of 10 to 99% by weight relative to the weight of the nanoparticles and a rutile crystalline phase (or anatase crystalline phase) in an amount of 25 to 90% by weight relative to the weight of the nanoparticles. In one embodiment, the TiO2-N nanoparticles have at least two crystalline phases of TiO2, namely, a brookite crystalline phase in an amount of 10 to 75% by weight relative to the weight of the nanoparticles and a rutile crystalline phase (or anatase crystalline phase) in an amount of 25 to 90% by weight relative to the weight of the nanoparticles. In another embodiment, the TiO2-N nanoparticles have a rutile crystalline phase (or anatase crystalline phase) and a brookite crystalline phase, each preferably present in an amount equal to about 50% by weight relative to the weight of the nanoparticles. In a particularly preferred embodiment, the TiO2-N nanoparticles have three crystalline phases of TiO2, namely, a brookite crystalline phase in an amount of 20 to 75% by weight relative to the weight of the nanoparticles, an anatase crystalline phase in an amount of 35 to 80% by weight, and a rutile crystalline phase in an amount of 35 to 40% by weight. In this particularly preferred embodiment of the present invention, the presence of a significant amount of brookite crystalline phase in the photocatalytic TiO2-N nanoparticles provides considerable advantages with respect to the photocatalytic properties of the nanofunctionalized support with respect to the nanoparticles. Without being bound by any theory, the superior photocatalytic activity of the brookite phase compared to the other two crystalline phases is thought to be related to the fact that, since photocatalytic activity depends on the number of TiO2 molecules per cell unit, the brookite phase, with its larger cell volume, also has a greater amount of surface oxygen available for photocatalysis.

[0060] Advantageously, in this particularly preferred embodiment of the present invention, where the support is nanofunctionalized with TiO2-N nanoparticles, the photocatalytic activity of the support occurs under irradiation with both ultraviolet and visible light (and therefore also under solar irradiation).

[0061] Furthermore, in one embodiment, the nanofunctionalized support with photocatalytic nanoparticles in the present invention may be further functionalized with one or more catalysts and / or biocides selected from a silver source (in the form of a silver salt, e.g., silver nitrate or silver sulfate, or silver nanoparticles), manganese(IV) oxide (MnO2) nanoparticles, zinc oxide (ZnO) nanoparticles, copper source (in the form of a copper salt, e.g., copper nitrate or copper sulfate, or copper nanoparticles), and combinations thereof.

[0062] In this embodiment, the nanofunctionalized support of the present invention therefore possesses catalytic activity and / or biocide activity even when not irradiated by a light source (ultraviolet light and / or visible light and / or sunlight), in addition to photocatalytic activity.

[0063] In one embodiment, the nanofunctionalized support with photocatalytic nanoparticles of the present invention is a support made of a polymer material characterized by nanoroughness and macroroughness as defined above, wherein the photocatalytic nanoparticles are present within the polymer material and / or on at least one inner surface and / or outer surface of the support in the form of a nanoparticle coating. The nanofunctionalized support with photocatalytic nanoparticles in the present invention has a density of 1 to 10 g / m². 2 Preferably 2-8 g / m 2 More preferably 4-7 g / m 2The material is preferably characterized by containing the nanoparticles in an amount contained between them. With regard to embodiments in which the photocatalytic nanoparticles are assumed to be present within the polymer material, or in which the photocatalytic nanoparticles are present both internally and as a nanoparticle coating, in this case, nanoroughness diffused both internally and on the surface can be described. With regard to embodiments in which the photocatalytic nanoparticles are assumed to be present only as a nanoparticle coating on at least one internal surface and / or external surface of the support, in this case, nanoroughness diffused only on the surface can be described. In one embodiment, the nanofunctionalized support of the present invention may be coated entirely or partially with photocatalytic nanoparticles. "Fully coated" means that the support has all internal and / or external surfaces coated with photocatalytic nanoparticles. In other words, the internal and / or external surfaces of the support have a coverage of greater than 95%, preferably greater than 98%, overall. "Partially coated" means that the internal and / or external surfaces of the support have a coverage of less than 95%, preferably less than 98%, overall. In this case, for example, only a portion of the surface of the support may be coated with photocatalytic nanoparticles. The nanoparticle coating has a thickness that is preferably between 1 and 5 μm, more preferably between 1.5 and 3 μm, and more preferably between 1.8 and 2.6 μm, as measured by an electron microscope.

[0064] Advantageously, due to the aforementioned nanoroughness and macroroughness values, the carrier in the present invention can be effectively coated with a nanoparticle coating of the aforementioned thickness, which demonstrates that it will conform to and adhere to the underlying polymer material over a long period of time.

[0065] In one embodiment of the present invention, the aforementioned nanofunctionalized carrier includes a plurality of channels and / or cells suitable for the passage of a fluid. The channels and / or cells preferably have a cross-section having a variable geometric shape, which is preferably selected from circular, hexagonal, square, triangular, rectangular, and combinations thereof. More preferably, the channels and / or cells define a fluid path having a variable geometric shape. The path is preferably selected from straight lines, meandering, helical, or combinations thereof.

[0066] In one embodiment, the nanofunctionalized carrier of the present invention has a structure selected from the group consisting of a layered structure, a woven mesh structure, a woven fabric structure, and a honeycomb structure having a variable number and / or shape of cells, wherein the shape is selected from the group consisting of, for example, a circle, a hexagon, a square, a triangle, a rectangle, and combinations thereof.

[0067] In one embodiment, the nanofunctionalized support of the present invention may include a plurality of layers of a variable number and size, each preferably having the structure described above.

[0068] The nanofunctionalized support in this embodiment preferably comprises at least two layers joined to each other by an interlock mechanism or a plug system.

[0069] The number of layers, their assembly method, and the choice of structure vary depending on the desired hydrodynamic properties.

[0070] Figure 8 shows a translucent nano-functionalized product manufactured from ABS by 3D printing, having a layered woven mesh structure, according to one embodiment of the present invention.

[0071] In a preferred embodiment, the nanofunctionalized carrier of the present invention has a honeycomb structure. In other words, the carrier having a honeycomb structure comprises a matrix of thin walls of polymer material defining a plurality of parallel conduits, which are open at both ends to allow passage of a fluid, preferably air and / or water. Advantageously, the plurality of conduits define a plurality of oxidation sites through the activation of the photocatalytic properties of nanoparticles present in the polymer material itself and / or in the form of a coating on the walls by incident photons, so that contaminants present in the fluid to be treated are adsorbed and decomposed as they pass through the plurality of conduits, resulting in the purification of the fluid. The honeycomb structure preferably contains CPSI (1 square inch) between 40 and 120, preferably 50 and 100, more preferably 50 and 70, and even more preferably 55 and 65. Chi (645.16mm) 2 )a Characterized by the values ​​of each cell.

[0072] In one embodiment, the nanofunctionalized carrier of the present invention has a structure selected from the group consisting of a spheroidal elliptic structure, preferably a spherical structure, or a cylindrical structure, a cuboidal structure, a cubic structure, a polyhedral structure, or a structure in the form of a "bead".

[0073] For the purposes of this invention, "beads" means pearl-like particles having at least one through-hole.

[0074] Preferably, in this embodiment, the structure is a structure having a characteristic size greater than 0.1 mm, preferably greater than 1 mm, preferably between 1 and 100 mm, and more preferably between 1 and 50 mm. For the purposes of the present invention, characteristic size means the average diameter (in the case of a spherical structure or sphere), the average height and / or average diameter (in the case of a cylindrical structure or bead), and the average size of the sides and / or bottom and / or slopes (in the case of a cuboid, cube, or polyhedron structure).

[0075] In a preferred embodiment, the nanofunctionalized carrier of the present invention has a spheroidal elliptic structure, preferably a spherical structure. Preferably, in this embodiment, the spheroidal elliptic structure, preferably a spherical structure, has an average diameter greater than 1 mm, preferably between 1 and 100 mm, and more preferably between 1 and 50 mm. In one embodiment, the nanofunctionalized carrier of the present invention has a spheroidal elliptic structure, preferably a hollow spherical structure.

[0076] In one embodiment, the nanofunctionalized support of the present invention has a spheroidal structure, preferably a spherical structure, having at least one through-hole, wherein the at least one through-hole has an average diameter smaller than the average diameter of the nanofunctionalized support having the spheroidal structure, preferably a spherical structure.

[0077] In a particularly preferred embodiment, the nanofunctionalized carrier of the present invention has a cylindrical structure. Preferably, in this embodiment, the cylindrical structure has an average diameter between 0.1 and 10 mm, preferably between 0.5 and 5 mm, and an average height between 1 and 50 mm, preferably between 2 and 20 mm. The nanofunctionalized carrier having a cylindrical structure is preferably a masterbatch.

[0078] In one embodiment, the nanofunctionalized carrier of the present invention has a hollow cylindrical structure.

[0079] In one embodiment, the nanofunctionalized support of the present invention has a cylindrical structure having at least one through hole, wherein the at least one through hole is preferably perpendicular or parallel to the axis (height) of the cylindrical structure. The at least one through hole preferably has an average diameter smaller than the average diameter of the nanofunctionalized support having the cylindrical structure according to the present invention.

[0080] The nanofunctionalized carrier of the present invention preferably comprises a plurality of such nanofunctionalized carriers or comprises a plurality of such nanofunctionalized carriers. In one embodiment, the aforementioned nanofunctionalized carriers are not constrained to one another. In an alternative embodiment, the aforementioned nanofunctionalized carriers are constrained to one another, preferably incorporated into a matrix, preferably a polymer matrix, and / or welded to one another and / or bonded to one another.

[0081] As described above, the nanofunctionalized carrier of the present invention preferably comprises or consists of a plurality of such nanofunctionalized carriers having a cylindrical structure or in the form of beads. In this embodiment, when the nanofunctionalized carrier is used in a filtration device for removing fluid contamination from organic contaminants (as further described below), the plurality of nanofunctionalized carriers having a cylindrical structure are preferably contained in the device in a special container.

[0082] The present invention further relates to a method for preparing nanofunctionalized supports as defined above. The method according to the present invention includes the following steps. (a) A step of preparing a carrier made of a polymer material having at least one inner surface and / or outer surface by a technique selected from the group consisting of 3D printing, injection molding or extrusion of the polymer material, wherein the polymer material is optionally a polymer material containing photocatalytic nanoparticles. (b) A step of applying a suspension of photocatalytic nanoparticles to at least one inner surface and / or outer surface of the support obtained in step (a) by a technique selected from the group consisting of "spray coating", "flow coating", "dip coating", "spin coating", "Meyer bar coating", "gravure coating", "knife coating", "kiss coating", "die coating", and "film transfer", wherein the nanoparticles are present in the suspension at a concentration between 1 and 30% by weight. If photocatalytic nanoparticles are present in the polymer material of step (a), step (b) may be optionally omitted.

[0083] In embodiments in which the photocatalytic nanoparticles are present within a polymer material forming a support, or in which the photocatalytic nanoparticles are present both within the polymer material and in the form of a nanoparticle coating, the polymer material containing the photocatalytic nanoparticles used in step (a) is preferably a polymer nanocomposite material. The polymer nanocomposite material is preferably obtained by compounding, i.e., by adding a powder containing photocatalytic nanoparticles to a polymer material, preferably in the form of pellets, and then by extruding a nanofunctionalized support made from the polymer material of the present invention, or alternatively, by extruding a polymer nanocomposite yarn, and then by processing by 3D printing or injection molding to produce a nanofunctionalized support made from the polymer material of the present invention.

[0084] In embodiments in which the carrier is further nanofunctionalized with one or more catalysts and / or biocides, it is possible to add one or more catalysts and / or biocides selected from a silver source (in the form of a silver salt, e.g., silver nitrate or silver sulfate, or silver nanoparticles), manganese(IV) oxide (MnO2) nanoparticles, zinc oxide (ZnO) nanoparticles, a copper source (in the form of a copper salt, e.g., copper nitrate or copper sulfate, or copper nanoparticles), and combinations thereof, during the compounding process. Advantageously, the possibility of functionalizing the polymer material before processing to produce the nanofunctionalized carrier in the present invention allows for standardization of production, thereby enabling the acquisition of different nanofunctionalized carriers containing the same amount of photocatalytic nanoparticles.

[0085] Advantageously, this embodiment optionally allows for a further second functionalization by coating the carrier with a photocatalytic nanoparticle coating by applying a suspension of photocatalytic nanoparticles (which have already been nanofunctionalized in step (a), and the photocatalytic nanoparticles are present within the polymer material), wherein the photocatalytic nanoparticles are the same as or different from those already present within the polymer material. Preferably, the carrier prepared according to step (a) may undergo further treatment adapted to impart further macroroughness. The further treatment is preferably selected from the group consisting of laser treatment, mold embossing, and combinations thereof. The mold itself can be designed and constructed so that the desired roughness is precisely formed during the mechanical action of the press and subsequent removal from the mold. This is particularly advantageous when the carrier is prepared by injection molding or extrusion techniques, which generally impart a value lower than the macroroughness value required by the present invention.

[0086] In a particularly preferred embodiment, the carrier of the present invention in step (a) is prepared using 3D printing.

[0087] Advantageously, the operation of forming the carrier using 3D printing effectively generates macro-roughness, which is problematic and undesirable in conventional applications, but is advantageous in the present invention because it can effectively improve the compatibility between the polymer material of the carrier and the photocatalytic nanoparticles.

[0088] In a preferred embodiment of the present invention, the suspension of photocatalytic nanoparticles in step (b) is a suspension in an organic solvent or a mixture of water and an organic solvent. The organic solvent is preferably selected from the group consisting of acetone, ethyl alcohol, isopropyl alcohol, methyl alcohol, and combinations thereof, and more preferably ethyl alcohol.

[0089] The aforementioned nanoparticles are preferably present in the suspension at a concentration between 5% and 15% by weight.

[0090] To ensure better application onto the substrate, the rheology of the suspension is preferably characterized by a density included between 0.6 and 1 g / cm 3 , more preferably between 0.7 and 0.9 g / cm 3 at 25 °C, and a viscosity included between 0.8 and 1.3 mPa·s, more preferably between 0.9 and 1.1 mPa·s.

[0091] As shown in the Examples section, the Applicant has found that, when comparing carriers made of the same polymeric material but having different values of nano-roughness and macro-roughness, and for the same weight of the applied photocatalytic nanoparticle solution, the amount of nanoparticles that effectively adhere to the carrier and thus functionalize the carrier is characterized by a nano-roughness included between 10 and 150 nm measured by electron microscopy, and a macro-roughness included between 100 and 600 μm measured by electron microscopy, and that the nano-roughness and macro-roughness are quite high (preferably between 1 and 5 g / m 2 , more preferably between 1.5 and 3 g / m 2 , even more preferably between 1.8 and 2.6 g / m 2 in the case of the nano-functionalized carriers of the present invention, which are diffused internally and / or superficially).

[0092] In an embodiment where the carrier is further nano-functionalized with one or more catalysts and / or biocides, it is possible to add to the suspension of photocatalytic nanoparticles in step (b) one or more catalysts and / or biocides selected from a silver source (in the form of a silver salt, for example silver nitrate or silver sulfate, or silver nanoparticles), manganese(IV) oxide (MnO2) nanoparticles, zinc oxide (ZnO) nanoparticles, a copper source (in the form of a copper salt, for example copper nitrate or copper sulfate, or copper nanoparticles), and combinations thereof.

[0093] In a particularly preferred embodiment where the carrier is a carrier nano-functionalized with photocatalytic TiO2-N nanoparticles as described above, the TiO2-N nanoparticles are preferably obtained by a method developed by the Applicant, the method comprising the following steps. (i) Prepare a suspension of TiO2 nanoparticles in water; (ii) Add the nitrogen doping agent to the suspension and mix until homogeneous; (iii) Dry the suspension to which the nitrogen doping agent has been added until a powder is obtained with residual moisture content between 0 and 15% by weight; (iv) The dried powder is calcined at a temperature between 400 and 600°C to obtain calcined powder; at will (v) The calcined powder is pulverized in a solvent to obtain a suspension of TiO2-N nanoparticles in the solvent; and optionally (vi) Dilute the suspension from step (v) with a solvent.

[0094] In an embodiment in which the method of the present invention includes a step (a) of preparing a carrier made of a polymer material, wherein the polymer material includes photocatalytic nanoparticles, and is obtained by compounding, that is, by adding a powder containing photocatalytic nanoparticles to the polymer material, the powder containing photocatalytic nanoparticles is a calcined powder obtained by carrying out steps (i) to (iv) of the above-described method in an embodiment in which the photocatalytic nanoparticles are TiO2-N nanoparticles.

[0095] In an embodiment of the method of the present invention, the method comprises the step (b) of applying a suspension of photocatalytic nanoparticles to at least one inner surface and / or outer surface of a carrier, wherein the photocatalytic nanoparticles are TiO2-N nanoparticles, the suspension is obtained by carrying out steps (i)-(v) or (i)-(vi) of the method described above.

[0096] The suspension of TiO2 nanoparticles in water in step (i) is a stable suspension prepared by the method described in WO200788151 of the same applicant, which is incorporated herein by reference in whole.

[0097] In particular, the suspension of TiO2 nanoparticles in water in step (i) is a suspension of TiO2 nanoparticles in anatase crystalline form.

[0098] The TiO2 nanoparticles in the suspension have a size that falls between 30 and 50 nm, as measured by methods known in the art, such as FEG-SEM (scanning electron microscope), TEM (transmission electron microscope), and DLS (dynamic light scattering). The polydispersity index of the nanoparticles is less than 0.3, preferably between 0.21 and 0.29, and more preferably between 0.216 and 0.286.

[0099] The concentration of TiO2 nanoparticles suspended in water is between 1 and 10% by weight, preferably between 2 and 8% by weight.

[0100] The suspension of nanoparticles is stable for a very long period without the occurrence of coagulation or agglomeration. Therefore, the suspension can be prepared by the method of WO2007881151 and then stored for a long period before being used as a starting product in the method of the present invention.

[0101] A method for obtaining a suspension of TiO2 nanoparticles in water, preferably in anatase crystalline form, comprises a first step of acid hydrolysis of titanium alkoxide in water in the presence of a nonionic surfactant, preferably Triton® X-100, at a temperature between 15 and 95°C, for a period of 12 to 72 hours.

[0102] Titanium alkoxides are selected from titanium methoxide, titanium ethoxide, titanium n-propoxide, titanium isopropoxide, titanium n-butoxide, and titanium isobutoxide. The preferred alkoxide is titanium propoxide.

[0103] The mineral acid used for the acid hydrolysis of titanium alkoxide is selected from hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, hydrobromic acid, and hydrogen iodide.

[0104] In step (ii), a nitrogen doping agent selected from inorganic ammonium salts and organic nitrogen compounds is added to a suspension of TiO2 nanoparticles in water, preferably in anatase crystalline form. The nitrogen doping agent is preferably selected from amines, organic ammonium salts, and inorganic ammonium salts. The nitrogen doping agent is preferably selected from diethanolamine, ammonium citrate, tetrabutylammonium hydroxide, and triethanolamine. Ammonium citrate has shown better results in terms of method and ease of drying of the suspension compared to other nitrogen doping agents, and is therefore a preferred nitrogen doping agent.

[0105] The nitrogen doping agent is added to the aqueous suspension of TiO2 in an amount between 2 and 6% by weight, preferably between 3 and 5% by weight.

[0106] The addition of a nitrogen doping agent to an aqueous suspension of TiO2 nanoparticles was performed under stirring, and the formation of a white gel was observed.

[0107] The suspension is then continuously stirred for 4 to 24 hours, i.e., until a homogeneous white suspension is obtained.

[0108] The resulting suspension contains 4-8 wt% TiO2 and 6-30 wt% nitrogen relative to the weight of TiO2. Preferably, the suspension contains 5-7 wt% TiO2 and 8-25 wt% nitrogen relative to the weight of TiO2.

[0109] The resulting suspension contains TiO2 nanoparticles having a size between 48 and 150 nm, measured as a Z-mean using DLS (Dynamic Light Scattering, Malvern Instruments). The 48-150 nm range means that the nanoparticles have a Z-mean equal to an integer or decimal number within the 48-150 nm range, and the polydispersity index is less than 0.3, preferably between 0.21 and 0.29, and more preferably between 0.216 and 0.286. Such polydispersity values ​​indicate excellent uniformity of nanoparticle size in the suspension. For example, if the Z-mean of the nanoparticles is equal to 49.9 and the polydispersity index is 0.221, this means that the suspension contains very uniform nanoparticles, almost all of which have an average diameter of approximately 49.9 nm.

[0110] The suspension of TiO2 nanoparticles thus obtained is dried in step (iii) by spray drying, or by heating in an electric or gas oven, or by microwave. The latter treatment is preferred because it is more efficient and faster than the use of conventional spray drying methods, and furthermore, microwave treatment makes it possible to obtain a powder with a lower degree of aggregation / clumping, making the subsequent optional grinding step (step (v)) more efficient.

[0111] The drying temperature is between 100 and 150°C, preferably between 110 and 140°C. Drying can be continued for 10 to 24 hours, preferably between 15 and 20 hours.

[0112] After drying, an ultrafine powder is obtained that has residual moisture content between 0 and 15% by weight and excellent fluidity.

[0113] The particle size of the powder, when calculated by laser diffraction using Sympatec's HELOS (model H0969), is less than 20 μm, preferably less than 15 μm. Preferably, 99% of the powder particles are less than 15 μm in size, and 90% are less than 11 μm in size. More preferably, 50% of the powder particles are less than 5.5 μm in size, and 10% are less than 2 μm in size.

[0114] The firing in step (iv) is preferably carried out at a temperature between 450 and 500°C.

[0115] Heating is performed by treating the dry powder in a muffle furnace or by microwave treatment. The latter treatment is preferred because it is more efficient and faster than conventional muffle furnace heating, and furthermore, microwave treatment allows for the acquisition of powder with a lower degree of agglomeration / coagulation, making subsequent optional grinding steps (step (v)) more efficient.

[0116] The firing process is carried out over a period of 1 to 2 hours, preferably using a ramp for 1 to 2 hours to reach the firing temperature. The heat gradient can be between 7 and 14°C per minute.

[0117] Without wishing to be bound by any particular theory, the applicant has found that during the firing process, nitrogen doping of TiO2 occurs, and nitrogen penetrates into TiO2 nanoparticles, occupying substitutional and / or interstitial positions within the TiO2 crystal lattice, i.e., within the crystal planes of TiO2.

[0118] The calcined powder is obtained as an aggregate of nitrogen-doped TiO2 (TiO2-N) and, under X-ray diffraction analysis, has at least one brookite crystalline phase in an amount of 10 to 99% by weight relative to the weight of the calcined powder.

[0119] In one embodiment, the calcined powder further comprises a rutile crystalline phase.

[0120] In one embodiment, the calcined powder comprising at least one brookite crystal phase and a rutile crystal phase further comprises an anatase crystal phase.

[0121] In one embodiment, the calcined powder contains 90-99% by weight of the TiO2 brookite crystalline phase relative to the weight of the calcined powder, with the remainder up to 100% by weight being rutile and / or anatase crystalline phase.

[0122] In one embodiment, the calcined TiO2-N powder contains two crystalline phases of TiO2: a brookite crystalline phase in an amount of 10 to 99% by weight relative to the weight of the calcined powder, and a rutile crystalline phase (or anatase crystalline phase) in an amount of 25 to 90% by weight relative to the weight of the calcined powder.

[0123] In one embodiment, the calcined TiO2-N powder contains two crystalline phases of TiO2, namely, a brookite crystalline phase in an amount of 10 to 75% by weight relative to the weight of the calcined powder and a rutile crystalline phase (or anatase crystalline phase) in an amount of 25 to 90% by weight relative to the weight of the calcined powder.

[0124] In one embodiment, the calcined powder comprises a rutile crystalline phase (or anatase crystalline phase) and a brookite crystalline phase, each preferably present in an amount equal to about 50% of the weight of the calcined powder.

[0125] In one embodiment, the calcined powder contains three crystalline phases of TiO2: 20 to 75% by weight of brookite crystalline phase, 35 to 80% by weight of anatase crystalline phase, and 35 to 40% by weight of rutile crystalline phase relative to the weight of the calcined powder.

[0126] Diffraction analysis did not reveal the presence of any phases other than the crystalline TiO2 phase mentioned above, therefore the calcined powder has a purity of over 95% by weight, preferably 99% by weight or more.

[0127] Without being bound by any theory, the applicant believes that the formation of doped TiO2 calcined powder containing at least one brookite crystalline phase is mainly due to the use of a TiO2 suspension obtained by the method of WO200788151, but also likely due to the combination of the use of this starting product and the aforementioned drying and calcination process.

[0128] The presence of the brookite phase is a surprising and unexpected result, considering that the starting product essentially consists of an anatase phase of TiO2. The brookite phase offers several significant advantages regarding the photocatalytic properties of the final suspension obtained at the end of the method.

[0129] The above method therefore makes it possible to obtain TiO2-N in nanoparticle form having photocatalytic properties similar to or better than those of TiO2-N photocatalysts known in the art, by forming a considerable amount of brookite crystal phase.

[0130] The calcined powder can be crushed and resuspended in a solvent (steps (v) and (vi) of the method described above) by grinding it in a solvent, preferably an organic solvent or water.

[0131] In step (v), the calcined powder is pulverized in a high-energy ball mill with the assistance of a solvent, such as water, acetone, ethyl alcohol, or a mixture thereof.

[0132] The grinding is carried out at a speed between 1000 and 2000 rpm for a time between 30 and 120 minutes, preferably between 80 and 100 minutes.

[0133] At the end of the grinding process, a highly concentrated suspension is obtained in the solvent, with the concentration of TiO2-N nanoparticles ranging from, for example, 15 to 30% by weight. In particular, the suspension obtained after grinding is a suspension of TiO2-N nanoparticles in an organic solvent, such as ethyl alcohol or acetone or a mixture thereof, or in water, or in a mixed solution of water and an organic solvent.

[0134] The size of nanoparticles is measured as a Z-mean using DLS (Dynamic Light Scattering, Malvern Instruments) and falls between 48 and 150 nm. The 48-150 nm range means that the nanoparticles have a Z-mean equal to an integer or decimal number within this range, and the polydispersity index is less than 0.3, preferably between 0.21 and 0.29, and more preferably between 0.216 and 0.286. Such polydispersity values ​​indicate excellent uniformity of nanoparticle size in the suspension. Therefore, for example, if the Z-mean of the nanoparticles is equal to 49.9 and the polydispersity index is 0.221, this means that the suspension contains very uniform nanoparticles, almost all of which have an average diameter of approximately 49.9 nm.

[0135] The suspension obtained at the end of step (v) may have too high a concentration and possess rheology that makes it unsuitable for some industrial applications, particularly for coating substrates.

[0136] For these reasons, the next step (vi) is also considered, in which the suspension is further diluted with the same solvent, preferably an organic solvent such as ethyl alcohol, acetone, water, or a mixture thereof, or water or a mixture thereof. The final concentration of TiO2-N powder in the solvent is therefore brought to a value between 0.1 and 20% by weight, preferably between 1 and 10% by weight.

[0137] The suspension of TiO2-N nanoparticles obtained at the end of the method (step (v) or step (vi)) contains nanoparticles having the same crystalline phase as shown in the calcined powder (step (iv)).

[0138] Surprisingly, the applicant has further found that the TiO2-N suspension obtained at the end of step (v) or (vi) described above remains stable for more than 6 months, despite the presence of a considerable amount of the brookite crystalline phase, which is the least stable crystalline phase of TiO2, as is known from the literature.

[0139] The applicant has further found that the carrier obtained by the method of the present invention (steps (a) and (b)), once nanofunctionalized with photocatalytic TiO2-N nanoparticles, has the same crystalline phase as the TiO2-N nanoparticles shown in the calcined powder of step (iv) of the above method and in the suspension of TiO2-N nanoparticles obtained in step (v) or optionally at the end of step (vi), whether they exist within the polymer material of the carrier and / or in the form of a nanoparticle coating.

[0140] In all the embodiments described above, the method of the present invention preferably includes a further step (b') prior to step (b). Step (b') is a step of pre-activating the carrier obtained in step (a) by immersing it in an organic solvent for an immersion time between 0.1 and 50 minutes, and then heat-treating it at a temperature between 30 and 60°C.

[0141] The organic solvent is preferably selected from the group consisting of acetone, ethyl alcohol, isopyroxine, methyl alcohol, and combinations thereof.

[0142] More preferably, the organic solvent is acetone.

[0143] The immersion time is preferably between 1 and 10 minutes.

[0144] The heat treatment is preferably carried out at a temperature between 35 and 55°C.

[0145] Advantageously, the pretreatment step (b') is found to be effective in further improving the compatibility between the polymer material of the support and the subsequent nanoparticle coating, and thus improving its photocatalytic performance over time.

[0146] In one embodiment, the method of the present invention includes a further step (c) after step (b). Step (c) is a step of heat-treating the obtained carrier at a temperature between 30 and 90°C for a processing time between 0.5 and 3 hours.

[0147] The temperature is preferably between 35 and 55°C.

[0148] The processing time is preferably between 0.5 and 2 hours.

[0149] Advantageously, the heat treatment process (c) allows for further improvement in the adhesion of the photocatalytic nanoparticle coating.

[0150] Advantageously, the selection of the carrier material in the present invention not only makes it possible to obtain a carrier having variable geometric shape, thickness, and form that can be adjusted as needed by 3D printing, injection molding, or extrusion, but also makes it possible to adjust its optical properties. In particular, in a particularly preferred embodiment, the nanofunctionalized carrier of the present invention is translucent or transparent, and more preferably transparent.

[0151] The applicant has found that by adjusting the above parameters (shape, thickness, geometric shape, opacity / transparency / transparency of the carrier, and the degree of roughness imparted to the carrier by the presence of nanoparticles in the form of a nanoparticle coating) the properties of the carrier and the photocatalytic performance can be changed, and since the contact time between the fluid and the nanofunctionalized carrier can be adjusted, the amount of photocatalytic nanoparticles present in and / or on the carrier, and optionally the proportion of irradiated light emission that passes through or is diffused by the carrier itself can be optimized.

[0152] Furthermore, the applicant has found that adjusting the nano-roughness and macro-roughness values ​​makes it possible to ensure the effective adhesion of photocatalytic nanoparticle coatings, which are generally considered to have little compatibility with carriers made of polymer materials, tend to peel off easily and separate easily, and thus degrade the photocatalytic performance of the carriers over time.

[0153] A further object of the present invention relates to the use of the aforementioned nanofunctionalized carriers as photocatalysts activated by ultraviolet and / or visible light (and / or, consequently, sunlight) for the removal of organic pollutants from fluids, preferably air and / or water.

[0154] The aforementioned organic pollutants are NO, NO X Preferably selected from NO2, COVs, SOVs, bacteria, molds, odors, and combinations thereof. In a preferred embodiment of the present invention, where the nanofunctionalized carrier with photocatalytic nanoparticles is made of a transparent or translucent polymer material, activation of the photocatalytic nanoparticles with ultraviolet and / or visible light has proven particularly effective because the transparent or translucent optical properties allow for utilization of up to 100% of the light emission, and thus enable effective utilization of the photocatalytic power of nanoparticles present in the polymer material and / or as a nanoparticle coating on at least one inner and / or outer surface of the carrier.

[0155] In embodiments in which the carrier is further nanofunctionalized with one or more catalysts and / or biocides as described above, the nanofunctionalized carrier in the present invention therefore possesses catalytic and / or biocide activity in addition to photocatalytic activity, and is therefore suitable for use in the decontamination of fluids, preferably air and / or water, even when not irradiated by a light source (ultraviolet and / or visible light and / or sunlight).

[0156] In a further aspect, the present invention also relates to a filtration device for removing organic contaminants from a fluid, preferably air and / or water, comprising, as described above, at least one nanofunctionalized carrier associated with at least one light source, the light source being configured to emit radiation in the ultraviolet and / or visible light spectrum and to irradiate the at least one nanofunctionalized carrier.

[0157] In one embodiment, the filtration device further includes at least one system for the aeration and / or distribution of a fluid, preferably air and / or water, which is configured to be favorable for contact with and / or passage through at least one nanofunctionalized carrier, so as to allow the fluid to pass through the filtration device itself.

[0158] In one embodiment, the filtration apparatus comprising at least one nanofunctionalized carrier and at least one light source of the present invention is characterized in that the at least one nanofunctionalized carrier completely surrounds and / or incorporates the at least one light source, and the at least one light source is preferably positioned so as not to obstruct the flow of fluid, preferably air and / or water, as it passes through the apparatus.

[0159] In embodiments of the present invention, the nanofunctionalized carrier comprises or consists of a plurality of nanofunctionalized carriers having a cylindrical structure or "bead" form that is not constrained by each other, wherein the plurality of carriers are preferably arranged to completely surround and / or incorporate the at least one light source, and the at least one light source is preferably positioned so as not to obstruct the flow of fluid, preferably air and / or water, as it passes through the device.

[0160] The at least one light source is preferably selected from light sources having a color temperature between 6000 and 7000K, preferably from LEDs. The at least one light source is also preferably 70 to 100 W / m 2 The light source has an irradiation dose that falls within the range of 500 to 1000 lm.

[0161] In embodiments in which the carrier is further nanofunctionalized with one or more catalysts and / or biocides as described above, the filtration device comprising at least one nanofunctionalized carrier in the present invention therefore possesses catalytic and / or biocide activity in addition to photocatalytic activity, and is therefore suitable for use in the removal of contaminants from fluids, preferably air and / or water, even in the absence of irradiation by a light source (ultraviolet and / or visible light and / or sunlight), for example, when at least one light source contained in the device itself is not acting.

[0162] The present invention advantageously allows for the customization of nanofunctionalized carriers, and therefore filtration devices containing them, depending on the application and the contaminants being treated.

[0163] Furthermore, considering the versatility of the methods and materials used to manufacture the nanofunctionalized carriers, the present invention advantageously enables miniaturization of the carriers and, therefore, filtration devices containing them.

[0164] Another advantage of the present invention is that it enables the optimization of the hydrodynamic system, particularly with respect to the possibility of changing the thickness and the geometric shape of the carrier, by creating an internal carrier design that provides multiple pathways, for example, which advantageously allows for increasing the contact time of contaminants present in the water and / or air to be treated. [Examples]

[0165] Example 1 806.0 g of ammonium dibase citrate is added to 19194.00 g of a 6% aqueous suspension of titanium dioxide (PH000025) obtained by the synthesis described in reference WO2007088151 in a 20 L reactor while stirring at room temperature. After stirring for 24 hours, the formation of a white suspension containing 0.498% nitrogen and 5.76% TiO2 (corresponding to 8.6 wt% nitrogen relative to TiO2) is observed. The size of the nanoparticles in the obtained suspension was measured by DLS (dynamic light scattering, Malvern Instruments) and was found to be equal to 49.9 nm. averageA value (hydrodynamic diameter Dz, and therefore corresponding to particle size) was obtained, and the polydispersity index (PdI) was 0.221.

[0166] Example 2 The suspension obtained in the same manner as in Example 1 was then dried by spray drying (Buchi Mini Spray Dryer B-290) at an inlet temperature of 130°C. The dried powder was thus obtained, and its particle size was evaluated by dry laser diffraction measurement (Sympatec dry laser, HELOS model (H0969)). The analytical results are explained in Figure 1. The obtained powder was very fine, with x99 = 14.21 μm (a value indicating that 99% of the powder particles were less than 14.21 μm in size), and had good fluidity.

[0167] Thermogravimetric DSC analysis (Figure 2) was also performed, showing that the mass decreased at low temperatures (-5.02% at 100°C) due to a reduction in residual moisture in the powder. This analysis also allowed for the identification of the precise calcination temperature for the dried powder in the next step, which falls between 450 and 500°C.

[0168] 400g of powder was placed in a heat-resistant pot measuring 41 × 26 × 6 cm. Firing was performed in an electric muffle furnace equipped with a programmer (Nabertherm model LH60 / 14). The thermal cycle was as follows: The first step consisted of heating from room temperature to 450°C at a gradient of 7°C / min over 2 hours, followed by a second step of residence time at 450°C for 1 hour. The recorded weight loss was 45%. The powder obtained after firing (referred to as fired powder) was subjected to diffraction analysis using the X-ray diffractometer (Panalytical X'pert pro) shown in Figure 3. The diffraction analysis performed was a quantitative analysis using the Rietveld refinement method to evaluate the proportion of crystalline phases and crystal size. The sample had the following diffraction concentrations in TiO2. [Table 1]

[0169] Finally, the calcined powder was ground in 99% ethanol at a speed of 1400 rpm for 80 minutes using a high-energy ball mill (E-Max Retsch). The final product obtained was a suspension of monodisperse nanoparticles with a size of approximately 90 nm, a polydispersity index of less than 0.2, and a TiO2-N concentration equal to approximately 20% by weight. Finally, the suspension was diluted with 96% ethanol to obtain a final TiO2-N concentration equal to 10% by weight in the suspension.

[0170] Example 3 Various translucent or opaque fabricated products with a honeycomb structure (HC) were manufactured by 3D printing. The manufactured samples have two faces of the same size but are distinguished by differences in thickness (5mm to 20mm) and / or the number / density of cells.

[0171] The samples were pre-treated by immersion in ethanol and then dried at a temperature of 50°C.

[0172] The suspension obtained in Example 2 was then applied by immersing the four samples. The excess suspension was subsequently removed, and the carrier was heat-treated in an oven at 50°C for 60 minutes.

[0173] The characteristics of the manufactured products obtained in this way are summarized in Table 1 below. [Table 2]

[0174] Example 4 The manufactured product HC-1 obtained as in Example 3 was analyzed by SEM (Scanning Electron Microscope, FEI model Quanta FEG 450) to evaluate the nano-roughness, macro-roughness, and thickness characteristics of the nanoparticle coating obtained by applying the suspension of TiO2-N nanoparticles obtained as in Example 2.

[0175] Figure 4 is an SEM image of a cross-section of a TiO2-N nanoparticle coating on a manufactured product. Figures 4a and 4b show two different magnified views generated by digital zooming in Figure 4, and it was possible to estimate the nanoroughness data of the sample from the magnified views. The nanoroughness measured at different locations in the cross-section is summarized in the table below, showing that it falls between 19 and 50 nm, centered around an average value of 35 nm. [Table 3]

[0176] The nanoparticle coating was also observed on the surface. SEM images of the TiO2-N coating surface are shown in Figure 5 and Figure 5a (a magnified view thereof). In this case as well, it was possible to estimate the nanoroughness values, which were measured at different locations in the cross-section and summarized in the table below. [Table 4]

[0177] The observed values ​​are consistent with those observed for the cross-section, and in this case, they fall within the range of 26-44 nm, centered around the average value of 33 nm.

[0178] The macro-roughness analysis was performed by evaluating the cross-section of the product HC-1 obtained by freeze-grinding in liquid N2. Figures 6 and 6a show SEM images obtained at two different magnifications, and it was possible to estimate the macro-roughness data of the sample from the magnifications. Macro-roughness values ​​collected at two points on the sample, showing equality of 253 μm and 308 μm, are given as examples. Considering the repetition of the product's structure due to 3D printing technology, it is possible to argue that the macro-roughness values ​​are significant at other points on the sample as well, and therefore actually represent the macro-roughness value of the product.

[0179] Figure 6b, in contrast, shows a further magnified view of Figure 6 generated by digital zoom, from which it was possible to estimate data regarding the thickness of the TiO2-N nanoparticle coating present in the manufactured product. The thickness was measured at three key points shown in the figure and was equal to 1.65 μm and 2.30 μm.

[0180] The above analysis, along with the measurement errors of each measuring instrument, is summarized in Figure 7.

[0181] Example 5: Comparative Experiment The tests were conducted on manufactured products HC-1, HC-2, HC-3, and HC-4, obtained in the same manner as in Example 3, and the concentration of contaminants (NOx) was determined by measuring the concentration as a function of time (expressed in ppbv) after irradiation with an LED with a color temperature of 3000K. X The reduction of ) was evaluated.

[0182] The results obtained were compared to those obtained as ceramic fabrications similarly nanofunctionalized with a nanoparticle coating of TiO2-N nanoparticles under similar irradiation conditions. However, in this case, the ceramic fabrications were functionalized according to the method described in the same applicant's patent application WO2018 / 207107, which includes the following steps. 97.00 g of the suspension obtained in the same manner as in Example 1 and 4.07 g of ammonium citrate were mixed in a 200 ml beaker, the temperature was set to 25°C, and the mixture was stirred for 24 hours to form a white, milky solution with concentrations of 5.76 wt% titanium dioxide and 0.49 wt% nitrogen. Next, 90.0 g of the suspension was applied using flow coating technology to a ceramic fabrication having a honeycomb structure, measuring 15 cm × 15 cm × 20 mm, with a cell count equal to 42 × 42 and 64 CPSIs. The prepared fabrication (HC-REF) was then subjected to a firing cycle of 3 hours at 500°C in a continuous electric furnace with a belt speed set to 4 m / h. After firing, the amount of nitrogen-doped titanium dioxide deposited was 5.23 g.

[0183] The results obtained for various samples are shown in Figure 9. NO was shown for the various samples tested.X The reduction trend clearly demonstrates that the nanofunctionalized products of the present invention are significantly more efficient than the ceramic products of the prior art. In particular, if we compare the product with the lowest-performing product of the present invention, namely product HC-4, which has a thickness of 5 mm and an amount of TiO2-N attached to it, the latter, in both cases under LED light irradiation, is more efficient than the ceramic product which is even thicker (20 mm) and has more photocatalytic nanoparticles attached to it. X This demonstrates even greater efficiency in terms of reduction. If we were to compare two manufactured products having the same dimensions (same thickness) instead, in this case, manufactured product HC-1 in the present invention (20 mm thick and 1.71 g of attached TiO2-N nanoparticles) is 5-6 times more efficient than a ceramic manufactured product (HC-REF) of the same dimensions but with a larger amount of attached photocatalytic nanoparticles.

[0184] Example 6: Comparative Experiment The tests were conducted on manufactured products HC-5, HC-6, HC-7, and HC-8, HC-9, HC-10, HC-11, HC-12, HC-13, and HC-14, obtained in the same manner as in Example 3. The reduction of contaminants (NO) was evaluated by measuring the concentration (expressed in ppbv) as a function of time after irradiation with an LED with a color temperature of 3000K.

[0185] The results are shown in Figure 10-14, and all manufactured products exhibit good photocatalytic performance.

[0186] Figures 15, 16, and 17 show graphs of the trends for the manufactured products HC-7, HC-8, HC-10, and HC-11 in the present invention, compared with the results obtained when the ceramic manufactured product HC-REF (details of which are described in Example 5) is irradiated under the same conditions.

[0187] In this case as well, the trend in NO reduction reported for the various samples tested clearly indicates that the nano-functionalized products of the present invention are significantly more efficient compared to the ceramic products of the prior art.

[0188] Example 7: Comparative Experiment A translucent, cubic product made of ABS, measuring 105mm x 105mm x 2mm and possessing a macro-roughness of essentially non-existent, i.e., less than 10μm (in other words, a product that can be considered "smooth"), was prepared by injection molding technology ("SAMPLE-S").

[0189] A second translucent product, of the same cubic shape and size, made from ABS, was prepared by 3D printing according to the present invention ("SAMPLE-R"). The product has a macro-roughness of 270 μm, as measured by SEM (in other words, a product that can be considered "rough").

[0190] Next, both products were initially pre-treated by washing with 96% ethanol and dried in a 50°C oven. Subsequently, the resulting suspension was functionalized by applying the "flow coating" technique, similar to Example 2. The products were then subjected to a 1-hour firing cycle at 50°C in a ventilated oven. The amount of nanoparticles adhering to product "SAMPLE-S" was 4 g / m². 2 On the other hand, the amount of nanoparticles attached to the manufactured product "SAMPLE-R" of the present invention is 19 g / m². 2 That was the case.

[0191] Next, the samples obtained in this manner were tested, using a 3000K LED as the light source to detect contaminants (NO, NO). X The reduction of NO2 was determined. Two tests, one for a "smooth" sample and the other for a "rough" sample of the present invention, are shown in Figures 18 and 19, respectively. In this case as well, the better performance of the products of the present invention is clearly evident when compared to the performance of products with different characteristics, in this case clearly a lower macro-roughness value, and therefore a lower ability of photocatalytic nanoparticles in terms of adhesion / functionalization. Examples of embodiments of the present invention are listed in the following sections [Aspect 1] to [Aspect 22]. [Aspect 1] A nanofunctionalized product comprising photocatalytic nanoparticles, wherein the product is made from a polymer material characterized by nanoroughness (3) between 10 and 150 nm as measured by an electron microscope and macroroughness (1), (2) between 100 and 600 μm as measured by an electron microscope, wherein the nanoroughness and macroroughness are diffused internally and / or on the surface, and the photocatalytic nanoparticles exist in the polymer material and / or on at least one internal surface and / or external surface of the product in the form of a nanoparticle coating. [Aspect 2] The nano-functionalized product according to embodiment 1, wherein the nano-roughness (3) is between 10 and 50 nm, preferably between 20 and 40 nm, and the macro-roughness (1) and (2) is between 200 and 300 μm. [Aspect 3] The nanofunctionalized product according to embodiment 1 or 2, wherein the polymer material comprises at least one (co)polymer selected from polymethyl methacrylate (PMMA), polyamide (PA), polycarbonate (PC), polylactic acid (PLA), polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile styrene acrylate (ASA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate glycol (PET-g), polyurethane (PU), polypropylene (PP), copolyester, and combinations thereof. [Aspect 4] The aforementioned photocatalytic nanoparticles, 2 TiO2 doped with elements selected from transition metals selected from Cu, Ni, Co, Mn, Fe, Cr, Mo, V, W, Y, and Sc; noble metals selected from Au, Ag, and Pt; rare earth elements selected from Ce, La, Pr, Nd, Te, and Yb; nonmetals selected from C, N, P, S, and F; and combinations thereof. 2 A nano-functionalized manufactured product according to any one of embodiments 1 to 3, wherein the nanoparticles are selected from the group consisting of the following: [Aspect 5] The photocatalytic nanoparticles are 1 to 10 g / m² 2 Preferably 2-8 g / m 2 More preferably 4-7 g / m 2 A nano-functionalized manufactured product according to any one of embodiments 1 to 4, which is present in an amount contained between the two. [Aspect 6] A nanofunctionalized product according to any one of the above embodiments, wherein the photocatalytic nanoparticles are nitrogen-doped TiO2 containing at least one brookite crystal phase in an amount of 10 to 99% by weight relative to the weight of the nanoparticles, and a rutile crystal phase in an amount of 25 to 90% by weight relative to the weight of the nanoparticles. 2 (TiO 2 -N) Nanoparticles, more preferably the TiO 2 -N nanoparticles further comprising an anatase crystal phase in an amount of 1 to 10% by weight or 25 to 90% by weight relative to the weight of the nanoparticles, wherein the nanoparticles are nano-functionalized products. [Aspect 7] A nanofunctionalized manufactured product according to any one of the above embodiments, wherein the nanoparticle coating has a thickness that falls between 1 and 5 μm, preferably 1.5 and 3 μm, and more preferably 1.8 and 2.6 μm, as measured by an electron microscope. [Aspect 8] A nanofunctionalized product according to any one of the above embodiments, comprising a plurality of channels and / or cells suitable for a fluid path, wherein the channels and / or cells have a cross section preferably selected from circular, hexagonal, square, triangular, rectangular and combinations thereof, and identify a fluid path having a variable geometric shape, wherein the path is preferably selected from straight, meandering, helical or combinations thereof. [Aspect 9] A nanofunctionalized manufactured product according to any one of the above embodiments, wherein the nanofunctionalized manufactured product has a structure selected from a layered structure, a woven mesh structure, a woven fabric structure, a honeycomb structure, and a combination thereof. [Aspect 10] A nanofunctionalized manufactured product according to embodiment 10, wherein the honeycomb structure is characterized by a CPSI value that falls between 40 and 120, preferably 50 and 100, more preferably 50 and 70, and even more preferably 55 and 65. [Aspect 11] A nanofunctionalized manufactured product according to any one of the above embodiments, comprising at least two layers having a structure selected from a layered structure, a woven mesh structure, a woven fabric structure, a honeycomb structure, and a combination thereof, wherein the at least two layers are joined to each other by an interlocking mechanism or a plug system. [Aspect 12] A nanofunctionalized manufactured product according to any one of embodiments 1 to 7, wherein the cylindrical structure preferably has an average diameter between 0.1 and 10 mm, preferably between 0.5 and 5 mm, and an average height between 1 and 50 mm, preferably between 2 and 20 mm. [Aspect 13] A nanofunctionalized product according to embodiment 12, comprising or consisting of a plurality of nanofunctionalized products having a cylindrical structure. [Aspect 14] A nanofunctionalized manufactured product according to any one of the above embodiments, wherein the manufactured product is opaque, translucent, or transparent, preferably translucent or transparent, and more preferably transparent. [Aspect 15] A method for preparing a nanofunctionalized product according to any one of embodiments 1 to 14, (a) A step of preparing a product made from a polymer material having at least one inner surface and / or outer surface by 3D printing, injection molding or extrusion of the polymer material, wherein the polymer material may be a polymer material containing photocatalytic nanoparticles; (b) A step of applying a suspension of photocatalytic nanoparticles onto at least one inner surface and / or outer surface of the product obtained in step (a) by a technique selected from the group consisting of "spray coating," "flow coating," "dip coating," "spin coating," "Meyer bar coating," "gravure coating," "knife coating," "kiss coating," "die coating," and "film transfer," wherein the nanoparticles are present in the suspension at a concentration between 1 and 30% by weight / weight. Includes, A method for preparing a nanofunctionalized product, wherein if the photocatalytic nanoparticles are present in the polymer material of step (a), step (b) can be optionally omitted. [Aspect 16] The method according to embodiment 15, further comprising step (b') of preactivating the product obtained in step (a) by immersing it in an organic solvent, preferably acetone, ethyl alcohol, isopropyl alcohol, methyl alcohol, or a combination thereof, for a time between 0.1 and 50 minutes prior to step (b), and then heat-treating it at a temperature between 30 and 60°C. [Aspect 17] The method according to embodiment 15 or 16, further comprising step (c) of heat-treating the obtained product at a temperature between 30 and 90°C for a time between 0.5 and 3 hours, after step (b). [Aspect 18] Use of a nanofunctionalized product according to any one embodiment of embodiments 1 to 14, wherein the photocatalyst is activated by ultraviolet light and / or visible light and / or sunlight for the removal of organic pollutants from a fluid, preferably air and / or water, and the organic pollutants are NO X Use of nanofunctionalized products preferably selected from among COV, SOV, bacteria, mold, odors, and combinations thereof. [Aspect 19] A filtration device for removing organic contaminants from a fluid, preferably air and / or water, comprising at least one nanofunctionalized product according to any one embodiment of embodiments 1 to 14, associated with at least one light source, wherein the light source is configured to emit ultraviolet and / or visible light spectrum radiation and irradiate the at least one nanofunctionalized product. [Aspect 20] The filtration apparatus according to embodiment 19, further comprising at least one ventilation and / or distribution system for a fluid, preferably air and / or water, wherein the at least one ventilation and / or distribution system is configured to allow the fluid to pass inside the filtration apparatus itself and preferably favorably allow the fluid to come into contact with and / or pass through the at least one nanofunctionalized product. [Aspect 21] A filtration apparatus according to embodiment 19 or 20, wherein the at least one nanofunctionalized product completely incorporates and / or incorporates the at least one light source, and the at least one light source is preferably positioned so as not to obstruct the flow of the fluid, preferably air and / or water, as the fluid passes through the apparatus. [Aspect 22] A filtration apparatus according to any one embodiment of embodiments 19 to 21, wherein the at least one light source has a color temperature between 6000 and 7000K and a power of 70 to 100 W / m². 2 A filtration device selected from a light source having an irradiation dose within a certain range and a luminous flux yield within a range of 500 to 1000 lm, preferably an LED.

Claims

1. A product nanofunctionalized with photocatalytic nanoparticles, the product being made from a polymer material characterized by nanoroughness (3) between 10 and 150 nm as measured by an electron microscope, and macroroughness (1) and (2) between 100 and 600 μm as measured by an electron microscope, wherein the nanoroughness and macroroughness are spread internally and / or on the surface, and the photocatalytic nanoparticles are present in the polymer material and / or on at least one internal surface and / or external surface of the product in the form of a nanoparticle coating. The photocatalytic nanoparticles are nitrogen-doped TiO2 containing at least one brookite crystal phase in an amount of 10 to 99% by weight relative to the weight of the nanoparticles, a rutile crystal phase in an amount of 25 to 90% by weight relative to the weight of the nanoparticles, and an anatase crystal phase in an amount of 1 to 10% or 25 to 90% by weight relative to the weight of the nanoparticles. ２ (TiO ２ -N) A nano-functionalized product comprising nanoparticles, wherein the total amount of the brookite crystal phase, rutile crystal phase, and anatase crystal phase does not exceed 100% by weight.

2. The nano-functionalized product according to claim 1, wherein the nano-roughness (3) is between 10 and 50 nm, and the macro-roughness (1) and (2) are between 200 and 300 μm.

3. The nanofunctionalized product according to claim 1 or 2, wherein the polymer material comprises at least one (co)polymer selected from polymethyl methacrylate (PMMA), polyamide (PA), polycarbonate (PC), polylactic acid (PLA), polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile styrene acrylate (ASA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate glycol (PET-g), polyurethane (PU), polypropylene (PP), copolyester, and combinations thereof.

4. The aforementioned photocatalytic nanoparticles, TiO ２ TiO2 doped with elements selected from transition metals selected from Cu, Ni, Co, Mn, Fe, Cr, Mo, V, W, Y, and Sc; noble metals selected from Au, Ag, and Pt; rare earth elements selected from Ce, La, Pr, Nd, Te, and Yb; nonmetals selected from C, N, P, S, and F; and combinations thereof. ２ A nano-functionalized manufactured product according to any one of claims 1 to 3, wherein the nanoparticles are selected from the group consisting of the following.

5. The photocatalytic nanoparticles are 1 to 10 g / m² ２ A nano-functionalized manufactured product according to any one of claims 1 to 4, which is present in an amount contained between the two.

6. The nano-functionalized product according to any one of claims 1 to 5, wherein the nanoparticle coating has a thickness that falls within the range of 1 to 5 μm as measured by an electron microscope.

7. A nanofunctionalized product according to any one of claims 1 to 6, comprising a plurality of channels and / or cells suitable for fluid pathways.

8. A nanofunctionalized manufactured product according to any one of claims 1 to 7, having a structure selected from a layered structure, a woven mesh structure, a woven fabric structure, a honeycomb structure, and a combination thereof.

9. The nanofunctionalized product according to claim 8, wherein the honeycomb structure is characterized by a cell value per square inch (645.16 mm²) that falls between 40 and 120.

10. A nano-functionalized product according to any one of claims 1 to 9, having a cylindrical structure.

11. The nanofunctionalized product according to claim 10, comprising or consisting of a plurality of nanofunctionalized products having a cylindrical structure.

12. The nanofunctionalized manufactured product according to any one of claims 1 to 11, wherein the manufactured product is opaque, translucent, or transparent.

13. A filtration device for removing organic contaminants from a fluid, comprising at least one nanofunctionalized product according to any one of claims 1 to 12, associated with at least one light source, wherein the light source is configured to emit ultraviolet and / or visible light spectrum radiation and irradiate the at least one nanofunctionalized product.

14. The filtration apparatus according to claim 13, further comprising at least one ventilation and / or distribution system for a fluid, wherein the at least one ventilation and / or distribution system is configured to allow the fluid to pass inside the filtration apparatus itself.

15. The filtration apparatus according to claim 13 or 14, wherein the at least one nanofunctionalized product completely incorporates and / or integrates the at least one light source.

16. The aforementioned at least one light source has a color temperature between 6000 and 7000 K and a power output of 70 to 100 W / m². ２ A filtration apparatus according to any one of claims 13 to 15, selected from light sources having an irradiation dose included in the range and a luminous flux yield included in the range of 500 to 1000 lm.

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