Preparation method of blackening doped photocatalyst, prepared product and application

Abstract

The invention discloses a preparation method of a blackening doping type photocatalyst, a prepared product and application, and belongs to the technical field of microbial pollution water treatment. The blackening doped photocatalyst comprises a carrier and an active component doped on the carrier, the carrier is black TiO2, and the active component is B particles. According to the blackening doping type photocatalyst, TiO2 is induced to be blackened through absolute ethyl alcohol, absorption of titanium dioxide in a visible light area is improved, meanwhile, the absorption edge of TiO2NTs is subjected to red shift to the visible light area through nonmetal B doping, the sterilization effect of TiO2NTs is improved, and the prepared catalyst is stable in sterilization effect and can be recycled.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment contaminated by microorganisms, and more specifically, relates to a preparation method of a blackened doped photocatalyst, a prepared product and application. Background Art

[0002] With the continuous development of industry and the acceleration of urbanization, domestic sewage and industrial sewage have increased. A large amount of sewage is discharged into natural water bodies without effective treatment, which will pollute natural water bodies and lead to further shortage of water resources. Therefore, the treatment of microorganisms in polluted water bodies is particularly important. At present, the chlorine sterilization technology and ultraviolet sterilization technology commonly used in sewage treatment plants have problems such as the production of by-products and high energy consumption. Therefore, in order to solve the problems of the above-mentioned commonly used sterilization technologies, it is necessary to develop new green, efficient and low-cost sewage treatment technologies.

[0003] Photocatalytic sterilization materials can undergo photocatalytic reactions in water bodies through the irradiation of light, producing bactericidal active species such as hydroxyl free radicals and reactive oxygen with oxidative ability, which oxidize and decompose the organic matter that makes up bacteria, thereby achieving a sterilization effect. 2 (TiO2) photocatalytic materials inherit the advantages of titanium dioxide being non-toxic, harmless and inexpensive, while also reducing the bandgap of titanium dioxide and thus having excellent photochemical properties. 2 There are limitations in the preparation methods of black TiO. For example, most calcination methods require harsh anaerobic conditions and strong reducing agents, and electrochemical reduction methods require expensive synthesis equipment and energy, which limits the development of black TiO 2 In addition, black TiO 2 The stability problem is another difficulty that limits its application. The development of doped photocatalysts provides a possible solution to the stability problem of materials.

[0004] After searching, patent CN110935449A discloses a high-efficiency and environmentally friendly black titanium dioxide-based photocatalyst and its preparation method, wherein the black titanium dioxide-based photocatalyst includes a load substrate and a co-doped black titanium dioxide loaded on the load substrate. The preparation method of the co-doped black titanium dioxide can be prepared by a sol-gel method, which includes the steps of: mixing a chelating agent, a co-doping source, and a solvent a, stirring for 5 to 15 minutes, adjusting the pH to 1 to 4, and obtaining a mixed solution A; mixing a titanium dioxide precursor, a stabilizer, and a solvent b, stirring for 10 to 20 minutes, and obtaining a mixed solution B; adding the mixed solution B to the mixed solution A under ice bath conditions, and stirring for 2 to 4 hours during the process to obtain a yellow transparent sol, and then aging for 6 to 10 hours to obtain a gel; drying at a temperature of 80 to 100°C to obtain a light yellow powder; and heat treating the obtained light yellow powder at 400 to 600°C for a period of time to finally obtain a co-doped black TiO2 . In this patent, stabilizers and chelating agents need to be added during the preparation process of co-doped black titanium dioxide to improve the stability and uniformity of the precursor solution, but these additives may have an adverse effect on the performance of the final catalyst. Specifically, these organic additives may form an organic film on the surface of the catalyst, blocking the absorption of visible light and reducing the photocatalytic activity. It may also occupy the active sites on the surface of the catalyst, reduce the contact opportunities between photogenerated carriers and reactants, increase the recombination probability of electron-hole pairs, and thus reduce the photocatalytic efficiency. In addition, these additives may decompose to produce organic by-products during the photocatalytic process, affecting the long-term stability of the catalyst. Therefore, although these additives help to improve the stability of the solution during the preparation process, they may have a negative impact on the final performance and application effect of the catalyst.

[0005] Based on this, it is of great significance to develop a method for preparing doped black titanium dioxide with high activity and high stability. Summary of the invention

[0006] 1. Problem to be solved

[0007] In view of the problem that the activity and stability of the existing doped black titanium dioxide are not high, the first object of the present invention is to provide a method for preparing a blackened doped photocatalyst;

[0008] The second object of the present invention is to provide a blackening doping type photocatalyst;

[0009] The third object of the present invention is to provide an application of the above-mentioned blackened doped photocatalyst, which is applied to photocatalytic sterilization.

[0010] 2. Technical solution

[0011] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0012] The first object of the present invention is to provide a method for preparing a blackened doped photocatalyst, the method comprising:

[0013] Step S1: Preparation of blackened B-doped TiO 2 Powder: Mix the boron precursor ethanol solution and the titanium precursor ethanol solution, hydrolyze, age, dry until the mixture is solid, and calcine to obtain blackened B / TiO 2 powder.

[0014] The method also includes step S2, preparing black B-doped TiO 2 NTs: Blackening of B-doped / TiO by hydrothermal treatment 2 The powder was then calcined to obtain blackened B-doped TiO 2 NTs.

[0015] The present invention uses low-cost anhydrous ethanol as a solvent for the titanium precursor to control the hydrolysis rate of the titanium precursor. Surprisingly, it is found that the added anhydrous ethanol acts as a reducing agent to in-situ induce the hydrolysis of TiO 2 , TiO 2 Oxygen vacancies are generated on the surface of TiO 2 Blackening, generating black TiO 2 , enhancing its ability to absorb visible light; during this period, trace amounts of B in the system 2 Modification, most of B is B atom or B 2 O 3 In the form of TiO 2 Surface, a small amount of B can partially enter TiO 2 Lattice, B atoms replace TiO 2 The O atoms in the lattice form boron-oxygen bonds (BO-Ti) and enter TiO 2 lattice, further promoting Ti 3+ The formation of species makes TiO 2 The absorption edge of the molecule is red-shifted, which expands the light response range to the visible light region. Under sunlight, hydroxyl radicals and active oxygen can also be generated in water, thus achieving a good bactericidal effect.

[0016] The doping of B not only introduces Ti 3+ , which also leads to changes in the surface structure of the material, making B / TiO 2 The density of states changes significantly, forming a new mid-band state, significantly narrowing the band gap and causing the absorption edge of the material to red-shift. Under visible light irradiation, hydroxyl radicals and reactive oxygen species can also be generated, thereby achieving a good bactericidal effect. These mid-band states not only promote the migration of photogenerated electrons, but also provide shallow trap sites to prevent the rapid recombination of photogenerated carriers, thereby improving the photocatalytic activity and stability. It is worth noting that Ti 3+ Although the reaction activity is high, its stability is poor and it is difficult to exist for a long time. Therefore, the Ti introduced by B doping 3+ , so that Ti 3+ The species exist stably on the catalyst surface, improving the chemical stability of the material.

[0017] The improvement in stability is based on B and Ti 3+ The transfer between B / TiO 2 During the preparation process, no stabilizer, chelating agent or other reagents used to stabilize the precursor were added, and the system was reductive as a whole, so Ti 3+ Stably exists on the catalyst surface, further, B promotes electron transfer, B mainly exists in the +3 valence state, forms a boron-oxygen bond (BO-Ti), and enters TiO2 lattice, further promoting Ti 3+ The formation of species, these Ti 3+ Species act as effective photogenerated carrier traps, reducing the recombination of electron-hole pairs and improving the photocatalytic activity. 3+ Maintain high activity during the reaction.

[0018] Furthermore, the weight ratio of the Ti element in the titanium precursor to the B element in the boron precursor is 1000:(0.5-2).

[0019] Boron usually exists in titanium dioxide in a +3 valence state. In boron-doped titanium dioxide, boron atoms can replace titanium atoms in the lattice to form boron-oxygen bonds (BO), thereby achieving doping. Boron atoms can enter the lattice of titanium dioxide and replace the positions of some oxygen atoms. This lattice doping can change the electronic structure and energy band structure of titanium dioxide, thereby affecting its photocatalytic performance. Part of the boron exists in the form of surface modification, that is, boron atoms or boron compounds are deposited on the surface of titanium dioxide nanotubes. This surface modification can change the surface properties of titanium dioxide, such as surface energy, hydrophilicity, etc., thereby affecting its photocatalytic activity and selectivity.

[0020] Furthermore, the titanium precursor is selected from one or more of tetrabutyl titanate, butyl titanate, titanium tetrachloride or tetraisobutyl titanate, preferably tetrabutyl titanate.

[0021] Furthermore, in step S1, the volume ratio of the titanium precursor to anhydrous ethanol is 1:(4-6);

[0022] The boron precursor is selected from one or more of boric acid, ammonium borate or sodium borate. The boron precursor is dissolved by water and ethanol solution. In the boric acid ethanol solution, the volume ratio of water to ethanol is 1: (4-6).

[0023] Furthermore, in step S1, the hydrolysis time is 2-4 hours, and the aging time is 12-16 hours, wherein in the hydrolysis step, the titanium precursor is hydrolyzed to generate a gel-like Ti(OH) 4 , age it for 12-16 hours, fully hydrolyze it, add ethanol, control the hydrolysis rate, and prevent the hydrolysis from being too fast and causing the gel to fail to form.

[0024] Furthermore, the mixture is calcined at a temperature of 500-600°C, for a time of 3-5h, and at a heating rate of 2-5°C / min.

[0025] Furthermore, the drying step of the aged mixture is as follows: the gel is dried in an oven at 80° C. for 12 hours to remove the solvent.

[0026] The method further comprises step S2, wherein the black B / TiO 2 The powder is mixed with alkali solution, and subjected to hydrothermal treatment at 120-180°C for 50-56h. The obtained product is calcined at 350-400°C for 4-6h to obtain blackened B-doped TiO 2 NTs.

[0027] Furthermore, in step S2, the hydrothermal treatment step is:

[0028] Step S2-1: blackening the B / TiO obtained in step S1 2 The powder and the alkali solution are stirred at room temperature to form a suspension, the pH of the suspension is adjusted to 13, and the suspension is hydrothermally reacted at 120-180°C for 5-6 hours and then crushed into powder;

[0029] Step S2-2, the material is subjected to hydrothermal treatment in an alkaline solution at 120-180° C. for 45-50 hours, and then filtered, the solid obtained is separated to prepare a suspension, stirred for 2-3 hours at a pH value of 2.5-3.0, centrifuged, and washed.

[0030] Through two hydrothermal treatments, more black B / TiO 2 Powder reaction to generate black B-doped / TiO 2 NTs, the amount of generated nanosheets is larger and the size is more uniform.

[0031] It should be noted that in the preparation of blackened B-doped / TiO 2 During the powdering process, the formation of boron-oxygen bonds (BO-Ti) is basically located in the TiO 2 Since the powder is basically granular, its specific surface area is small, and the number of boron-oxygen bonds (BO-Ti) formed is small. In this application, B is doped to induce the formation of TiO 2 NTs(TiO 2 Nanotubes), accumulated on TiO during hydrothermal treatment 2 The boron atoms and boron compounds on the powder surface are dispersed and can be evenly distributed on the TiO 2 NTs surface, obtaining more surface active sites and being able to penetrate deep into TiO 2 lattice, forming boron-oxygen bonds (BO-Ti) at deeper lattices, thereby improving the photocatalytic activity.

[0032] Furthermore, the alkali solution in step S2-1 is a sodium hydroxide solution or a potassium hydroxide solution, preferably a sodium hydroxide solution, and the sodium hydroxide aqueous solution preferably has a concentration of 10M;

[0033] The temperature of the hydrothermal treatment is 120-180°C, preferably 150°C;

[0034] The hydrothermal treatment time is 5-6 hours, preferably 5 hours.

[0035] Furthermore, in step S2-2, after cooling and breaking the agglomerates, the hydrothermal treatment is continued, the temperature of the hydrothermal treatment is 120-180°C, preferably 150°C, and the pH value is adjusted to 2.5-3.0 with an acid solution, and the acid solution is preferably dilute hydrochloric acid, or dilute sulfuric acid, which can achieve pH adjustment;

[0036] The hydrothermal treatment time is 45-50 hours, preferably 48 hours.

[0037] Furthermore, in step S2, the blackened B / TiO 2 The calcination temperature of the powder is 350-450°C, preferably 400°C; the calcination time is 4-6h, preferably 5h; the heating rate is 1-3°C / min, preferably 1°C / min.

[0038] The second object of the present invention is to provide a blackened doped photocatalyst, which is prepared by the above-mentioned preparation method, and the blackened doped photocatalyst comprises a carrier and an active component doped on the carrier; wherein the carrier is black TiO 2 , the active component is B particles.

[0039] Furthermore, the doping amount of B in the blackened doped photocatalyst is 0.03%-0.15%wt%.

[0040] Too little B doping will cause the band gap to change, and Ti 3+ Too few species will affect the improvement of photocatalytic performance; too much B doping may cause material lattice distortion, introduce excessive defects and trap sites, occupy active sites, increase the recombination probability of electron-hole pairs, reduce the number of carriers involved in the photocatalytic reaction, and reduce photocatalytic performance.

[0041] Furthermore, the black TiO 2 Anatase black TiO 2 .

[0042] It should be noted that TiO 2 Rutile is generally easier to form at high temperatures, while anatase is more difficult to form at high temperatures. In this application, the addition of B is beneficial to stabilize TiO 2 , so that at a lower temperature (350-700 ° C) anatase phase black TiO 2 , avoiding the structural defects of materials caused by high temperature treatment. Compared with the rutile phase, anatase black TiO 2It has higher photocatalytic activity, its crystal structure is relatively loose, it has a higher specific surface area, can adsorb more reactant molecules, has a higher photogenerated carrier separation efficiency and the number of surface active sites, thereby improving the photocatalytic efficiency; and it exhibits good chemical stability in acid and alkaline solutions, is suitable for different water environments, and achieves efficient sterilization effect.

[0043] Furthermore, the black TiO 2 Black TiO 2 NTs, titanium dioxide nanotubes have a unique tubular structure, which is conducive to the separation of photogenerated electrons and holes, reducing the recombination probability of photogenerated carriers, and the specific surface area is much larger than that of titanium dioxide particles. The high specific surface area can provide more active sites and has a higher adsorption capacity, which is conducive to the contact between the catalyst and the reactant, thereby improving the efficiency of the photocatalytic reaction. The oxygen vacancies on its surface can promote the electrons in B and TiO 2 The transfer between them improves the stability of the catalyst.

[0044] The black TiO 2 The size of NTs is 15nm. The smaller diameter of nanotubes increases the specific surface area of ​​the material and provides more active sites, thereby enhancing light absorption and photocatalytic activity. The small particle size helps to shorten the transmission path of photogenerated carriers, reduce the recombination of electron-hole pairs, and improve the transmission efficiency of photogenerated carriers. In addition, the smaller diameter of nanotubes increases the surface energy of the material, improves chemical stability, and reduces the deactivation of the catalyst during the reaction. Boron mainly exists in the +3 valence state, forming a boron-oxygen bond (BO-Ti), entering TiO 2 lattice, further promoting Ti 3+ The formation of species, these Ti 3+ The species act as effective traps for photogenerated carriers, reducing the recombination of electron-hole pairs and improving the photocatalytic activity.

[0045] The third purpose of the present invention is to provide the application of the above-mentioned blackened-doped photocatalyst in water treatment and disinfection, which includes the steps of: mixing the blackened-doped photocatalyst with bacteria-containing water, first adsorbing it in the dark, and then irradiating it with visible light; wherein the blackened-doped photocatalyst is the above-mentioned blackened-doped photocatalyst.

[0046] The purpose of the present invention is to solve the problem of harmful byproducts produced by traditional chlorine sterilization technology in the field of sewage treatment and the high cost of ultraviolet sterilization technology, thereby providing a blackening doping type photocatalyst modification, preparation method and application, the blackening doping type photocatalyst uses low-cost anhydrous ethanol to induce blackening, improves the titanium dioxide nanotubes (TiO 2 NTs) in the visible light region, and non-metallic B doping is used to make TiO 2The absorption edge of NTs red-shifts to the visible light region, increasing the 2 The bactericidal effect of NTs. The catalyst is simple to prepare, has a stable bactericidal effect, and can be recycled. In addition, the catalyst has a broad-spectrum bactericidal effect, is low in cost, and is green and environmentally friendly, and has broad application prospects in actual water bodies.

[0047] 3. Beneficial effects

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) A method for preparing a blackened doped photocatalyst according to the present invention uses anhydrous ethanol to induce TiO 2 NTs are black, and the blackened B-doped / TiO 2 In the powder, most of the boron is in the form of B atoms or B 2 O 3 In the form of TiO 2 Surface, a small amount of boron enters TiO 2 Lattice, replacing TiO 2 The O atoms in the lattice form boron-oxygen bonds (BO-Ti) and enter TiO 2 lattice, further promoting Ti 3+ The formation of species effectively improves the reaction activity and stability of the catalyst;

[0050] (2) The blackened doped photocatalyst of the present invention has a carrier of black TiO 2 NTs, TiO 2 NTs have a larger specific surface area, provide more active sites, and have a higher adsorption capacity, which is conducive to the contact between the catalyst and the reactant, thereby improving the efficiency of the photocatalytic reaction; the rich oxygen vacancies on its surface can promote the electrons in B and TiO 2 Transfer between them to improve the stability of the catalyst;

[0051] (3) The blackened doped photocatalyst of the present invention is beneficial to stabilize the black TiO 2 , which allows the formation of anatase phase at a lower temperature, has a higher specific surface area, higher photogenerated carrier separation efficiency and a higher number of surface active sites, thereby improving the photocatalytic efficiency; and exhibits good chemical stability in acid and alkaline solutions, is suitable for different water environments, and achieves efficient sterilization, which can effectively solve the problems of high energy consumption, high cost, and poor continuous sterilization effect caused by the use of ultraviolet sterilization in traditional sewage sterilization treatment technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0053] Figure 1 The X-ray diffraction pattern (XRD) of the product D3 obtained in Example 2;

[0054] Figure 2 (a) is a high magnification transmission electron microscopy (HRTEM) image of the product D1 obtained in Comparative Example 1, and (b) is a high magnification transmission electron microscopy (HRTEM) image of the product D3 obtained in Example 2;

[0055] Figure 3 This is a scanning electron microscope image (SEM) of the product D3 obtained in Example 2;

[0056] Figure 4 (a) is an EDS layered image of the Ti element in the product D3 obtained in Example 2, and (b) is an EDS layered image of the B element in the product D3 obtained in Example 2;

[0057] Figure 5 (a) is white TiO 2 NTs (purchased from Aladdin), (b) is the product D1 obtained in Comparative Example 1, and (c) is the product appearance of the product D3 obtained in Example 2;

[0058] Figure 6 The UV-visible diffuse reflectance spectrum (UV-vis) of the product D3 obtained in Example 2;

[0059] Figure 7 The sterilization effect diagram of the product D3 prepared in Example 2 of the present invention and the product D6 prepared in Example 5;

[0060] Figure 8 The sterilization effect diagrams are of the product D2 prepared in Example 1 of the present invention, the product D3 prepared in Example 2, the product D4 prepared in Example 3, the product D5 prepared in Example 4, and the product D1 prepared in Comparative Example 1;

[0061] Fig. 9 The graph is a cyclic sterilization effect diagram of the product D3 obtained in Example 2 and the product D1 obtained in Comparative Example 1;

[0062] Fig.10 This is a diagram showing the bactericidal effect of the product D3 obtained in Example 2 on Escherichia coli and Bacillus subtilis;

[0063] Fig.11This is a diagram showing the bactericidal effect of the product D3 obtained in Example 2 on bacteria in actual water;

[0064] Fig.12 The product prepared in Comparative Example 1 and white TiO 2 Diagram of the bactericidal effect of NTs. DETAILED DESCRIPTION

[0065] The following detailed description of exemplary embodiments of the present invention refers to the accompanying drawings, which form a part of the description, and in which exemplary embodiments of the present invention that can be implemented are shown as examples. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention, it should be understood that other embodiments can be implemented and various changes can be made to the present invention without departing from the spirit and scope of the present invention. The following more detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but is only for the purpose of illustrating and not limiting the description of the characteristics and features of the present invention, so as to propose the best mode for performing the present invention and to enable those skilled in the art to implement the present invention. Therefore, the scope of the present invention is limited only by the appended claims.

[0066] It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention. As used herein, the terms "parallel" and "perpendicular" are not limited to their strict geometric definitions, but include tolerances for reasonable and inconsistent machining or human errors.

[0067] The present invention provides a blackening doping type photocatalyst. The carrier is TiO 2 , the active component is B particles.

[0068] The application of the above-mentioned blackened doped photocatalyst in water disinfection.

[0069] The method for sterilizing and disinfecting water comprises: mixing a blackened doped photocatalyst with water containing bacteria, adsorbing the mixture in the dark, and then irradiating the mixture with visible light.

[0070] The blackened doped photocatalyst prepared by the present invention has excellent broad-spectrum bactericidal performance, and the bactericidal effect is stable and can be recycled, thus having broad application prospects.

[0071] In order to achieve a better sterilization effect, the concentration of the blackened doped photocatalyst in the water body is 0.1-0.5 mg / mL.

[0072] The light-proof adsorption time can be selected in a wide range, for example, the light-proof time is 20-40 minutes, preferably 30 minutes.

[0073] The irradiation time is 1-2h, and the light intensity is 80-120mW / cm 2 , preferably 100 mW / cm 2 .

[0074] The visible light was provided by a xenon lamp (400-780 nm) with an ultraviolet filter UVIRCut400 (transmitting 400-780 nm).

[0075] The bacteria are Escherichia coli or Bacillus subtilis, and the concentration of the bacteria is 10 6 -10 7 CFU / mL.

[0076] The present invention will be described in detail below by way of examples. In the following examples, the drugs and medicaments are all conventional commercial products.

[0077] The present invention is further described below in conjunction with specific examples.

[0078] Comparative Example 1

[0079] This comparative example is black TiO 2 The preparation process of NTs includes the following steps:

[0080] (1) Precursor TiO 2 Preparation of powder:

[0081] 22 mL of tetrabutyl titanate was mixed with 100 mL of anhydrous ethanol and then ultrasonicated to obtain a tetrabutyl titanate ethanol solution, which was stirred and hydrolyzed for 2 h at room temperature to obtain a transparent sol. The sol was then aged at room temperature for 12 h to obtain a gel, which was dried in an oven at 80 ° C for 12 h to remove the solvent, and the white solid obtained after drying was ground to obtain a white powder, which was then calcined at 500 ° C in a muffle furnace for 3 h. The calcined solid was ground to obtain a gray-black powder, which is black TiO 2 powder.

[0082] (2) Preparation of blackened titanium dioxide nanotubes:

[0083] Weigh 1g of the obtained gray-black titanium dioxide powder, stir it with 20mL of 10mol / L sodium hydroxide aqueous solution at room temperature for 2h to form a suspension, put it into a stainless steel reactor lined with Teflon, keep it at 150℃ for 5h, and then crush it into powder. The material is further treated in 10mol / L sodium hydroxide aqueous solution at 150℃ for 48h. The separated solid is then suspended in 500mL of distilled water, the pH value of the solution is adjusted to 2.5 with dilute hydrochloric acid and stirred for 2h, then centrifuged and washed with distilled water until the pH value reaches 6.5. The material is placed in an oven for drying, and the obtained product is calcined at 400℃ for 5h. The obtained solid is ground to obtain gray-black TiO 2 NTs, denoted as D1.

[0084] Example 1

[0085] This example is a black B / TiO 2 The preparation process of NTs includes the following steps:

[0086] Step S1: Mixing a boron precursor ethanol solution and a tetrabutyl titanate ethanol solution by a sol-gel method, aging and drying the mixture until it reaches a solid state, and then calcining the mixture to obtain a blackened anatase phase B / TiO 2 Powder; specifically, comprising the steps of:

[0087] S1-1, measuring 22 mL of tetrabutyl titanate and mixing with 100 mL of anhydrous ethanol, and then sonicating to obtain a tetrabutyl titanate ethanol solution;

[0088] S1-2, adding an ethanol solution of boric acid, wherein the amount of boric acid added is based on an elemental mass ratio of B to Ti of 0.5:1000, wherein the boric acid is first dissolved in deionized water, and then ethanol is added, wherein the volume ratio of water to ethanol is 1:5, to obtain an ethanol solution of boric acid, and stirring and hydrolyzing at room temperature for 2 hours to obtain a sol having an elemental mass ratio of B to Ti of 0.5:1000 (the theoretical doping amount of B is 0.05wt%);

[0089] Step S1-3, aging the sol at room temperature for 12 hours to obtain a gel, drying the gel in an oven at 80° C. for 12 hours to remove the solvent, and grinding the white solid obtained after drying to obtain a white powder;

[0090] Step S1-4, calcining in a muffle furnace at 500°C for 3h, grinding the calcined solid to obtain blackened B-doped TiO 2 powder.

[0091] Step S2: treating the blackened boron-doped titanium dioxide powder by hydrothermal method and then calcining to obtain blackened boron-doped titanium dioxide powder. 2 NTs, specifically, comprising the steps of: 2 1 g of the powder was weighed and stirred with 20 mL of 10 mol / L sodium hydroxide aqueous solution at room temperature for 2 h to form a suspension, which was then placed in a stainless steel reactor lined with Teflon and kept at 150 ° C for 5 h before being crushed into powder. The material was further treated in 10 mol / L sodium hydroxide aqueous solution at 150 ° C for 48 h. The separated solid was then suspended in 500 mL of distilled water, the pH value of the solution was adjusted to 2.5 with dilute hydrochloric acid and stirred for 2 h, then centrifuged and washed with distilled water until the pH value reached 6.5. The material was placed in an oven for drying, and the resulting product was calcined at 400 ° C for 5 h. The resulting solid was ground to obtain blackened B / TiO 2 NTs, denoted as D2.

[0092] Example 2

[0093] The method described in Example 2 was used for implementation, except that the element mass ratio of B to Ti was 1.0:1000, that is, in step S1, an ethanol solution of boric acid was added to the ethanol solution of tetrabutyl titanate before hydrolysis for 2 h to obtain a sol with an element mass ratio of B to Ti of 1.0:1000 (the theoretical doping amount of B was 0.10 wt%), and finally B-doped TiO 2 NTs, denoted as D3, the appearance of D3 is as follows Figure 5 shown.

[0094] The product D3 obtained in Example 2 was subjected to X-ray diffraction, and the specific results are as follows: Figure 1 .

[0095] according to Figure 1 The diffraction peaks of the anatase phase

[101] and

[200] show that the product D3 obtained in Example 2 is anatase TiO 2 .

[0096] Figure 2 a is a high magnification transmission electron microscopy (HRTEM) image of the product D1 obtained in Comparative Example 1, and b is a high magnification transmission electron microscopy (HRTEM) image of the product D3 obtained in Example 2. Figure 2 It can be observed that both the product D1 prepared in comparative example 1 of the present invention and the product D3 prepared in example 2 are nanotube structures, and the outer diameter of the product D3 prepared in example 2 is 15 nm.

[0097] Figure 3 This is a scanning electron microscope image (SEM) of the product D3 obtained in Example 2. It can be seen from the image that the product D3 obtained in Example 2 is in the shape of nanotubes.

[0098] To further determine the distribution of each element, the product D3 obtained in Example 2 was subjected to energy dispersive spectroscopy (EDS). The specific results are as follows: Figure 4 shown.

[0099] Figure 4 a is the EDS layered image of the Ti element in the product D3 obtained in Example 2, Figure 4 b is the EDS layered image of the B element in the product D3 obtained in Example 2; Figure 4 The bright spots of element B in b are evenly distributed, indicating that element B is 2 NTs are evenly distributed, and the B element is evenly doped into TiO 2 NTs.

[0100] Figure 6 The UV-visible diffuse reflectance spectrum of the product D3 obtained in Example 2 is shown in Table 2. Compared with the undoped TiO 2NTs, blackened B / TiO 2 The absorption edge of NTs is red-shifted, and the light response range is effectively widened. The absorption edge is red-shifted to about 500nm. Due to its smaller bandgap width, the top of the valence band moves up, and the bottom of the conduction band moves down, the generated photogenerated holes have stronger oxidation ability, and the photogenerated electrons have stronger reduction ability, thus showing higher redox efficiency in the photocatalytic reaction. The enhanced absorption in the visible light region can more effectively generate active species required for sterilization, such as hydroxyl radicals (·OH) and superoxide radicals (·O 2 - ), which may have higher efficiency and better effect in sterilization applications.

[0101] Example 3

[0102] The method described in Example 2 was used for the implementation, except that the elemental mass ratio of B to Ti was 1.5:1000, that is, in step S1, a boric acid ethanol solution was added to the tetrabutyl titanate ethanol solution before hydrolysis for 2 h to obtain a sol with an elemental mass ratio of B to Ti of 1.5:1000 (the theoretical doping amount of B was 0.15 wt%), and finally a blackened B / TiO 2 NTs, denoted as D4.

[0103] Example 4

[0104] The method described in Example 2 was used for the implementation, except that the elemental mass ratio of B to Ti was 2.0:1000, that is, in step S1, a boric acid ethanol solution was added to the tetrabutyl titanate ethanol solution before hydrolysis for 2 h to obtain a sol with an elemental mass ratio of B to Ti of 2.0:1000 (the theoretical doping amount of B was 0.20 wt%), and finally a blackened B / TiO 2 NTs, denoted as D5.

[0105] The products prepared in Comparative Example 1 and Examples 1-4 were used as samples for ICP-MS analysis to understand the actual content of doped B. The results showed that the B element in the product D2 prepared in Example 1 was 0.03%, the B element in the product D3 prepared in Example 2 was 0.07%, the B element in the product D4 prepared in Example 3 was 0.11%, and the B element in the product D5 prepared in Example 4 was 0.15%, as shown in Table 1.

[0106] Table 1 ICP detection of the actual content (wt%) and theoretical content (wt%) of B in the materials prepared in Examples 2 to 5

[0107]

[0108] Example 5

[0109] This example is a black B / TiO2 The preparation process of NTs includes the following steps:

[0110] The boron precursor ethanol solution and tetrabutyl titanate ethanol solution were mixed by sol-gel method, aged and dried until the mixture reached solid state, and then calcined to obtain blackened B-doped TiO 2 Powder; specifically, the method comprises the steps of measuring 22 mL of tetrabutyl titanate and mixing with 100 mL of anhydrous ethanol, ultrasonically treating the mixture, obtaining a tetrabutyl titanate ethanol solution, adding a boric acid ethanol solution, stirring and hydrolyzing the mixture at room temperature for 2 hours, and obtaining a sol having an elemental mass ratio of B to Ti of 1:1000 (the theoretical doping amount of B is 0.1 wt%). The sol is then aged at room temperature for 12 hours to obtain a gel, the gel is dried in an oven at 80°C for 12 hours to remove the solvent, the white solid obtained after drying is ground to obtain a white powder, and then calcined at 500°C for 3 hours in a muffle furnace, and the calcined solid is ground to obtain a blackened B-doped / TiO 2 Powder, recorded as D6.

[0111] Example 6

[0112] The antibacterial activity of blackened boron-doped titanium dioxide nanotubes and blackened titanium dioxide nanotubes in different proportions was evaluated. The bacteria used in the experiment were common Escherichia coli, and the density of the bacterial solution was adjusted to 10 9 CFU;

[0113] Among them, the experiment used different ratios of black doped B / TiO 2 NTs and black TiO 2 NTs are the materials prepared in Comparative Example 1 and Examples 1-4;

[0114] Weigh 15 mg of the obtained material and add it to 30 mL of sterile water for 0.5 h. Add 30 uL of E. coli solution and stir to adsorb for 0.5 h in the dark. Take samples after 0.5 h of adsorption. Turn on the xenon light source for 2 h of sterilization and take samples every half an hour.

[0115] The obtained samples were diluted in the same gradient and added into Luria-Bertani solid medium (10 g / L peptone, 5 g / L yeast powder, 5 g / L NaCl, 15 g / L agar powder). After spreading on the plates, they were sealed with sealing film and placed in an incubator for overnight culture for 18 h to count the number of colonies.

[0116] Depend on Figure 7 The ratio of the residual bacteria concentration to the initial bacteria concentration in Example 5 and Example 2 shows that the D3 blackened B / TiO 2 NTs compared with D6 blackened B / TiO prepared in Example 5 2 The bactericidal effect of the powder is improved.

[0117] Depend on Figure 8 The ratio of the residual bacteria concentration to the initial bacteria concentration in Comparative Example 1 and Examples 1-4 shows that the bactericidal effect of the product D1 obtained in Comparative Example 1 is not ideal. The bactericidal effects of the product D2 obtained in Example 1, the product D3 obtained in Example 2, the product D4 obtained in Example 3, and the product D5 obtained in Example 4 show that the blackened B / TiO2 with different B doping amounts has a good effect on the bactericidal effect. 2 NTs all improved the bactericidal effect to a certain extent, among which the product D3 prepared in Example 2 had the best bactericidal effect, indicating that the doping ratio of B was 0.10%wt% for TiO 2 The bactericidal rate of NTs was significantly improved.

[0118] Example 7

[0119] The method described in Example 6 was followed, except that the product D3 obtained in Example 2 and the product D1 obtained in Comparative Example 1 were recycled four times, and the killing effect of the recycled materials on Escherichia coli was tested. The results are as follows: Fig. 9 As shown. Fig. 9 From the sterilization effect diagram of the product D3 prepared in Example 2 after four cycles, it can be seen that the sterilization effects of D3 and D1 after four cycles are compared. The cyclic sterilization effect of the product D3 prepared in Example 2 is much higher than that of the product D1 prepared in Comparative Example 1, indicating that the product D3 prepared in Example 2 has good stability while maintaining good sterilization performance.

[0120] Example 8

[0121] The method described in Example 6 was followed, except that the bacteria used in the experiment were 10 9 CFU of Bacillus subtilis, the test results are as follows Fig.10 As shown. Fig.10 The comparison of the bactericidal effects of the product prepared in Example 2 on Escherichia coli and Bacillus subtilis shows that Example 2 also has a good bactericidal effect on Bacillus subtilis, indicating that the bactericidal performance of the product D3 prepared in Example 2 has a broad spectrum.

[0122] Example 9

[0123] The sterilization experiment was carried out according to the method of Example 6. The difference was that when the sterilization effect of the product D3 prepared in Example 2 was tested, the water used was the actual water from different sampling points. The sterilization effect was as follows: Fig.11 shown.

[0124] Depend on Fig.11From the graph showing the bactericidal effect of the product D3 prepared in Example 2 on bacteria in actual water bodies, it can be seen that the product D3 also has a good bactericidal effect in actual water bodies, indicating that the product D3 prepared in Example 3 of the present invention has practical applicability.

[0125] Example 10

[0126] The sterilization experiment was carried out according to the method of Example 6. The difference was that when the sterilization effect of the product D3 prepared in Example 2 was tested, the water used was the actual water from different sampling points. The sterilization effect was as follows: Fig.11 shown.

[0127] Depend on Fig.11 From the graph showing the bactericidal effect of the product D3 prepared in Example 2 on bacteria in actual water bodies, it can be seen that the product D3 also has a good bactericidal effect in actual water bodies, indicating that the product D3 prepared in Example 3 of the present invention has practical applicability.

[0128] Comparative Example 2

[0129] The sterilization experiment was carried out according to the method described in Example 6, except that the material used in the experiment was white TiO 2 NTs (purchased from Aladdin), bactericidal effect Fig.12 shown.

[0130] Comparative Example 1 Blackened TiO 2 The photocatalytic sterilization ability of NTs is much greater than that of the white TiO 2 The photocatalytic bactericidal ability of NTs indicates that blackening can improve the photocatalytic bactericidal ability of TiO 2 NTs play an important role in the practical application of photocatalytic sterilization.

[0131] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0132] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0133] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a blackened doped photocatalyst, characterized in that: Includes steps: Preparation of blackened B-doped / TiO2 powder: mixing a boron precursor ethanol solution and a titanium precursor ethanol solution, hydrolyzing, aging, drying until the mixture is solid, and calcining at 500-600° C. to obtain a blackened B-doped / TiO2 powder.

2. The preparation method according to claim 1, characterized in that: The weight ratio of the Ti element in the titanium precursor to the B element in the boron precursor is 1000:(0.5-2).

3. The preparation method according to claim 1, characterized in that: The titanium precursor is selected from one or more of tetrabutyl titanate, butyl titanate, titanium tetrachloride or tetraisobutyl titanate; The boron precursor is selected from one or more of boric acid, ammonium borate or sodium borate, and uses water and ethanol as dispersion media to form a boron precursor ethanol solution.

4. The preparation method according to claim 3, characterized in that: The hydrolysis time is 2-4h and the aging time is 12-16h.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The method also includes the steps of preparing blackened B-doped / TiO2 NTs: treating blackened B-doped / TiO2 powder by a hydrothermal method and then calcining the powder to obtain blackened B-doped / TiO2 NTs.

6. The preparation method according to claim 5, characterized in that: During the hydrothermal treatment, the blackened B-doped / TiO2 powder was mixed with an alkali solution and hydrothermally treated at 120-180°C for 50-56h. The resulting product was calcined at 350-400°C for 4-6h to obtain blackened B-doped / TiO2 NTs.

7. A blackened doped photocatalyst, prepared by the preparation method according to any one of claims 1 to 6, characterized in that: It comprises a carrier and an active component doped on the carrier, wherein the carrier is black TiO2, the active component is B particles, and the doping amount of B in the blackened doped photocatalyst is 0.03%-0.15%wt%.

8. The blackening doping type photocatalyst according to claim 7, characterized in that: The black TiO2 is black TiO2NTs.

9. The blackening doping type photocatalyst according to claim 7, characterized in that: The black TiO2 is anatase black TiO2.

10. An application of the blackened doped photocatalyst according to any one of claims 7 to 9, characterized in that: Used in water treatment and disinfection, the blackened doped photocatalyst is mixed with bacteria-containing water, adsorbed, and degraded under visible light.

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