Composite nanomaterials, methods of making and using the same

Abstract

The application provides a composite nanometer material and a preparation method and application thereof, and the composite nanometer material comprises X@TiO2-Au nanoparticles, and the X@TiO2-Au nanoparticles are X@TiO2 heterostructures coated with Au nanoparticles; wherein the X@TiO2 heterostructure is composed of water-soluble (X:Yb, Er, Tm) nanoparticles and TiO2 nanoparticles; X is a visible light absorbing material, and comprises CaF2 and NaYF4; compared with the prior art, the composite nanometer material provided by the application can degrade organic matters including rhodamine B (Rh B) under one or more of near-infrared light irradiation conditions, visible light irradiation conditions and ultraviolet light irradiation conditions; and the growth of bacteria can be inhibited; the preparation method is simple and easy to operate, and the prepared composite nanometer material has high application performance.

Description

Technical Field

[0001] This invention relates to the field of photocatalytic disinfection, sterilization, and water purification, and particularly to a composite nanomaterial, its preparation method, and its application. Background Technology

[0002] Environmental pollution is a growing global concern, and the use of nanomaterials for environmental remediation has become a hot topic in high-tech competition among nations. Many countries have invested heavily in research and development and are actively promoting its industrialization. Several products have emerged, and titanium dioxide (TiO2), due to its non-toxicity, good chemical stability, optical and catalytic properties, is widely used and is currently the most widely applied photocatalyst.

[0003] However, most visible and near-infrared light cannot be absorbed by TiO2; and the rapid recombination of its photogenerated support severely affects its catalytic performance. In other words, the conditions for photocatalytic degradation and sterilization in existing technologies are stringent, limiting their applicability. Summary of the Invention

[0004] The main objective of this invention is to provide a composite nanomaterial, its preparation method, and its application, aiming to solve the problems of the harsh conditions required for photocatalytic degradation and sterilization in existing technologies.

[0005] To achieve the above objectives, the present invention provides a composite nanomaterial comprising X@TiO2-Au nanoparticles, wherein the X@TiO2-Au nanoparticles are an X@TiO2 hybrid coated with Au nanoparticles.

[0006] The X@TiO2 hybrid is composed of water-soluble (X: Yb, Er, Tm) nanoparticles and TiO2 nanoparticles.

[0007] X is a visible light absorbing material, including CaF2 and NaYF4.

[0008] Furthermore, X is CaF2.

[0009] The present invention also provides a method for preparing the composite nanomaterial as described in any one of the above claims, comprising the steps of:

[0010] Provides oil-soluble (X:Yb,Er,Tm) nanoparticles.

[0011] A ligand exchange reagent was prepared by mixing ethanol, chloroform, and 0.2 M sodium citrate solution in a volume ratio of 1:1:1.

[0012] The oil-soluble (X:Yb,Er,Tm) nanoparticles were stirred with the ligand exchange reagent at room temperature for >12h to obtain water-soluble (X:Yb,Er,Tm) nanoparticles.

[0013] The water-soluble (X:Yb,Er,Tm) nanoparticles were mixed with diethylenetriamine and tetrabutyl titanate was added. The mixture was reacted at 150-250°C for 20-40 h and then separated to obtain X@TiO2 nanocomposite material.

[0014] The X@TiO2 nanocomposite material was mixed with an aqueous solution of Au nanoparticles and stirred and reacted in the dark at 20-30°C for 40-80 min to obtain the composite nanomaterial.

[0015] Wherein, X is a visible light absorbing material, including: CaF2 and NaYF4.

[0016] Furthermore, the oil-soluble (X:Yb,Er,Tm) nanoparticles are obtained by mixing calcium or sodium salts with ytterbium salts, erbium salts, thulium salts, and NH4F stock solution to obtain a reaction mixture.

[0017] Prepare a mixture of NaOH, ethanol, deionized water and oleic acid.

[0018] The reaction mixture is mixed with the liquid mixture and heated at 170–190°C for 30–50 h to obtain the oil-soluble (X:Yb,Er,Tm) nanoparticles.

[0019] Furthermore, the process of stirring at room temperature for >12 hours also includes centrifugation purification of the stirred product using a water / ethanol solvent combination.

[0020] Furthermore, the centrifugation purification speed is 9000-12000 rpm; the centrifugation purification time is 8-12 min.

[0021] Furthermore, the separation process includes, in sequence, ethanol centrifugation, drying, and crystallization.

[0022] Furthermore, the crystallization treatment temperature is 300–400°C; the crystallization treatment duration is 2.5–3.5 h.

[0023] The present invention also provides an application of the composite nanomaterial as described in any one of the above claims or the composite nanomaterial prepared by any one of the above claims, wherein the composite nanomaterial is mixed with a solution of organic matter to be degraded under dark conditions to obtain a mixture; the mixture is then exposed to light conditions to achieve the degradation of the organic matter to be degraded.

[0024] The illumination conditions include one or more of near-infrared light illumination conditions, visible light illumination conditions, and ultraviolet light illumination conditions.

[0025] The present invention also provides an application of the composite nanomaterial as described in any one of the above claims or the composite nanomaterial prepared by any one of the above preparation methods, wherein the composite nanomaterial is added to a bacterial solution and mixed under dark conditions to obtain a mixture; the mixture is then irradiated with one or more of near-infrared light, visible light and ultraviolet light to inhibit bacterial growth.

[0026] The beneficial effects achieved by this invention are as follows:

[0027] The composite nanomaterials provided by this invention can utilize not only ultraviolet and visible light, but also some near-infrared light to achieve charge and energy transfer, thereby extending the lifetime of photogenerated holes and improving photocatalytic performance. Under one or more of near-infrared, visible, and ultraviolet light irradiation conditions, the composite nanomaterials provided by this invention can degrade organic matter, including Rhodamine B (Rh B), and can also inhibit bacterial growth.

[0028] The method for preparing composite nanomaterials provided by this invention is simple and easy to operate, and the resulting composite nanomaterials have strong applicability. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 The above are characterization and analysis diagrams of the composite nanomaterials prepared in Example 1 of this invention; wherein, Figure 1 (A) is its transmission electron microscope (TEM) image (50 nm); Figure 1 (B) is its transmission electron microscope (TEM) image (10 nm); Figure 1 (C) is its transmission electron microscope (TEM) image (5nm); Figure 1 (D) is its X-ray photoelectron spectroscopy (XPS) spectrum;

[0031] Figure 2 The following are energy dispersive spectroscopy (EDS) analyses of the products at each stage of the preparation process in Example 1 of this invention; wherein, Figure 2 (A) is a comparison of the FTIR spectra of oil-soluble (CaF2:Yb,Er,Tm) nanoparticles and water-soluble (CaF2:Yb,Er,Tm) nanoparticles; Figure 2 (B) is a comparison of the luminescence spectra of oil-soluble (CaF2:Yb,Er,Tm) nanoparticles and water-soluble (CaF2:Yb,Er,Tm) nanoparticles. Figure 2 (C) is a comparison of the ultraviolet-visible-near-infrared absorption spectra of oil-soluble (CaF2:Yb,Er,Tm) nanoparticles, CaF2@TiO2 nanocomposites, and composite nanomaterials. Figure 2 (D) is a comparison of the luminescence spectra of oil-soluble (CaF2:Yb,Er,Tm) nanoparticles, CaF2@TiO2 nanocomposites, and composite nanomaterials;

[0032] Figure 3 This is a comparison chart of the degradation effects of different catalysts on RhB under different light conditions in Example 2 of the present invention; wherein, Figure 3 (A) is a comparison chart of absorbance measurement results for each group under ultraviolet light irradiation conditions; Figure 3 (B) is a comparison chart of the absorbance measurement results of each group under visible light conditions; Figure 3 (C) is a comparison chart of absorbance measurement results for each group under sunlight conditions (mixed illumination conditions of near-infrared, visible and ultraviolet light);

[0033] Figure 4 This is a comparison chart of the antibacterial performance of different catalysts under near-infrared light irradiation conditions in Example 3 of the present invention.

[0034] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementations and not for limiting the scope of protection of this invention.

[0037] Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, can be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention. It should be understood by those skilled in the art that, as an explanation of this application, without affecting the actual understanding of the technical solutions of this application, "Energy (KeV)" can represent electronic energy (KeV), "Transmittance (%)" can represent transmittance (%), "Luminescence (au)" can represent luminescence (au), "Absorbance (au)" can represent absorbance (au), "C / CO" can represent instantaneous concentration / original concentration, and "NIR irradiation" can represent near-infrared light irradiation (radiation).

[0038] When numerical ranges are given in the examples, it should be understood that, unless otherwise stated in the invention, both endpoints of each range and any value between the two endpoints may be used. Test methods in the following examples that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers. Unless otherwise specified, all materials or reagents required in the following examples are commercially available.

[0039] To address the problems of stringent conditions in existing photocatalytic degradation and sterilization technologies, this invention provides a composite nanomaterial comprising X@TiO2-Au nanoparticles, wherein the X@TiO2-Au nanoparticles are an X@TiO2 hybrid coated with Au nanoparticles.

[0040] The X@TiO2 hybrid is composed of water-soluble (X:Yb,Er,Tm) nanoparticles and TiO2 nanoparticles.

[0041] X represents materials that absorb visible light, including CaF2 and NaYF4.

[0042] The composite nanomaterials provided by this invention can utilize not only ultraviolet and visible light, but also some near-infrared light to achieve charge and energy transfer, thereby extending the lifetime of photogenerated holes and improving photocatalytic performance. Under one or more of near-infrared, visible, and ultraviolet light irradiation conditions, the composite nanomaterials provided by this invention can degrade organic matter, including Rhodamine B (Rh B), and can also inhibit bacterial growth.

[0043] It should be noted that TiO2 has a band gap of 3.2 eV and can only absorb ultraviolet light (wavelength (λ) < 400 nm), accounting for only 5% of the solar spectrum. Approximately 43% of visible light (400 nm < λ < 780 nm) and 52% of near-infrared light (780 nm < λ < 2500 nm) cannot be absorbed by TiO2. Furthermore, the rapid recombination of the photogenerated support severely affects its catalytic performance. Therefore, the application of titanium dioxide (TiO2) as a photocatalyst in existing technologies requires relatively stringent application conditions.

[0044] The gold nanoparticles in this composite nanomaterial act as excellent electron traps, and when irradiated by incident light, they can generate plasmon resonance in the visible light region. In this composite nanomaterial, Au nanoparticles are deposited on the TiO2 surface, forming a Schottky barrier with TiO2, which effectively traps electrons, reduces electron-hole recombination, prolongs the lifetime of photogenerated holes, and improves photocatalytic performance.

[0045] Furthermore, this composite nanomaterial can improve the utilization rate of sunlight by capturing near-infrared light, thereby enhancing photocatalytic performance. The CaF2 or NaYF4 in this composite nanomaterial can absorb near-infrared light. The absorbed near-infrared light is then converted into visible light that can be absorbed by Au nanoparticles and ultraviolet light that can be absorbed by TiO2 through charge and energy transfer between nanocomponents via Foster resonance energy transfer (FRET) and plasmon resonance energy transfer (PRET). Specifically, the absorbed near-infrared light is converted into charge and energy by Tm during the energy transfer process. 3+ Emitting ultraviolet light, by Er 3+ It emits visible light.

[0046] Therefore, under sunlight, this composite nanomaterial can effectively utilize ultraviolet, visible, and near-infrared light, greatly improving the efficiency of light utilization.

[0047] Furthermore, X is CaF2. Experiments have shown that CaF2 is a good upconversion material with low phonon energy, weak nonradiative relaxation, and high radiation efficiency. Therefore, X in this composite nanomaterial is preferably CaF2.

[0048] This invention also provides a method for preparing composite nanomaterials as described in any of the above claims, comprising the following steps:

[0049] Provides oil-soluble (X:Yb,Er,Tm) nanoparticles.

[0050] A ligand exchange reagent was prepared by mixing ethanol, chloroform, and 0.2 M sodium citrate solution in a volume ratio of 1:1:1.

[0051] Oil-soluble (X:Yb,Er,Tm) nanoparticles were stirred with a ligand exchange reagent at room temperature for >12 h to obtain water-soluble (X:Yb,Er,Tm) nanoparticles.

[0052] Water-soluble (X:Yb,Er,Tm) nanoparticles were mixed with diethylenetriamine and tetrabutyl titanate was added. The mixture was reacted at 150-250℃ for 20-40 h and then separated to obtain X@TiO2 nanocomposite material.

[0053] The X@TiO2 nanocomposite material was mixed with an aqueous solution of Au nanoparticles and stirred for 40–80 min under dark conditions at 20–30 °C to obtain the composite nanomaterial.

[0054] Wherein, X represents materials that absorb visible light, including CaF2 and NaYF4.

[0055] Specifically, a certain mass of X@TiO2 nanocomposite material was added to a beaker containing a certain amount of Au NPs solution, and the mixture was stirred and reacted in the dark at 20-30°C for 40-80 min. The mixture was then separated by centrifugation with ethanol and deionized water, and the resulting pink precipitate was dried at 60°C overnight (≥12 h) to obtain the composite nanomaterial.

[0056] The method for preparing composite nanomaterials provided by this invention is simple and easy to operate, and the resulting composite nanomaterials have strong applicability. Furthermore, this composite nanomaterial perfectly solves the problems of low light utilization efficiency and rapid electron-hole recombination in TiO2 photocatalysts.

[0057] Furthermore, the oil-soluble (X:Yb,Er,Tm) nanoparticles are obtained by mixing calcium or sodium salts with ytterbium salts, erbium salts, thulium salts, and NH4F stock solution to obtain a reaction mixture.

[0058] Prepare a mixture of NaOH, ethanol, deionized water and oleic acid.

[0059] The reaction mixture was combined with the liquid mixture and heated at 170–190 °C for 30–50 h to obtain oil-soluble (X:Yb,Er,Tm) nanoparticles. When the reaction temperature was <170 °C, the crystallization of the oil-soluble (X:Yb,Er,Tm) nanoparticles was poor, thus affecting the luminescence properties of the final product. If the reaction temperature was >190 °C, carbonization easily occurred in the liquid mixture, affecting the synthesis of oil-soluble (X:Yb,Er,Tm) nanoparticles. If the reaction time exceeded 50 h, the particle size of the obtained oil-soluble (X:Yb,Er,Tm) nanoparticles would increase, thus affecting the luminescence properties of the final product.

[0060] Furthermore, the process of stirring at room temperature for >12 hours also includes centrifugation purification of the stirred product using a combination of water and ethanol solvents.

[0061] Furthermore, the centrifugation purification speed is 9000–12000 rpm; the centrifugation purification time is 8–12 min. When the centrifugation purification speed is below 9000 rpm, water-soluble (X:Yb, Er, Tm) nanoparticles cannot be obtained. When the centrifugation purification speed is above 12000 rpm, the product aggregates and is difficult to dissolve in subsequent steps, affecting the preparation of the final product.

[0062] Furthermore, the separation process includes ethanol centrifugation, drying, and crystallization in sequence.

[0063] Furthermore, the crystallization treatment temperature is 300–400℃, and the crystallization treatment time is 2.5–3.5 h. If the crystallization treatment temperature is too low or the time is too short, the crystallization of the material will be poor, thus affecting the luminescence properties of the final product. If the temperature is too high, the solvent will carbonize, affecting the synthesis of the material. If the reaction time is too long, the particle size of the material will increase, thus affecting the luminescence properties of the final product.

[0064] The present invention also provides an application of the composite nanomaterial prepared by any of the above methods or the composite nanomaterial prepared by any of the above methods, wherein the composite nanomaterial is mixed with a solution of organic matter to be degraded under dark conditions to obtain a mixture; the mixture is exposed to light conditions to achieve the degradation of the organic matter to be degraded.

[0065] The illumination conditions include one or more of the following: near-infrared light illumination conditions, visible light illumination conditions, and ultraviolet light illumination conditions.

[0066] This invention also provides an application of the composite nanomaterial prepared by any of the above-mentioned methods, characterized in that the composite nanomaterial is added to a bacterial solution and mixed under dark conditions to obtain a mixture; the mixture is then irradiated with one or more of near-infrared light, visible light, and ultraviolet light to inhibit bacterial growth. Preferably, when applied to inhibit bacterial growth in the human body, irradiation with a 980nm laser is preferred.

[0067] To further illustrate the present invention, the following examples are provided:

[0068] Example 1

[0069] (1) Oil-soluble (CaF2:Yb,Er,Tm) nanoparticles

[0070] The reaction mixture was prepared by mixing CaCl2 (0.39 mmol), YbCl3·6H2O (0.1 mmol), ErCl3·6H2O (0.1 mmol), TmCl3·6H2O (0.01 mmol) with the stock solution of NH4F (2 mmol of NH4F dissolved in 4 ml of deionized water) in a flask to obtain the reaction mixture.

[0071] Prepare a mixture of NaOH (1.2g), ethanol (8mL), deionized water (8mL), and OA (20mL).

[0072] The reaction mixture was added to the mixture and stirred thoroughly to obtain a milky white colloidal solution. The milky white colloidal solution was then transferred to a 100 ml PTFE-lined autoclave and heated to 180 °C. This temperature was maintained for 36 h, after which heating was stopped and the mixture was cooled to room temperature. The product was washed with ethanol, centrifuged, and harvested to obtain oil-soluble (CaF2:Yb,Er,Tm) nanoparticles (i.e., oleic acid-coated CaF2:Yb,Er,Tm on-conversion nanocrystals), which were dispersed in cyclohexane for further utilization.

[0073] (2) Synthesis of water-soluble (CaF2:Yb,Er,Tm) nanoparticles

[0074] Take 60.0 mg of the oil-soluble (CaF2:Yb,Er,Tm) nanoparticles obtained in step (1) and place them together with a ligand exchange reagent consisting of 4.00 mL ethanol, 4.00 mL chloroform, and 4.00 mL of 0.2 M sodium citrate solution in a beaker and stir overnight at room temperature (≥12 h). Then, purify the synthesized citrate-coated CaF:Yb,Er,Tm nanoparticles by centrifugation (10000 rpm, 10 min) with a water / ethanol solvent combination, and vacuum dry at 60 °C for 12 h to obtain water-soluble (CaF2:Yb,Er,Tm) nanoparticles.

[0075] (3) Synthesis of CaF2@TiO2 nanocomposites

[0076] 30 mg of the water-soluble (CaF2:Yb,Er,Tm) nanoparticles obtained in step (2) were added to isopropanol (20 mL), followed by diethylenetriamine (40 μL). After stirring and sonicating for 30 min, tetrabutyl titanate (2 mL) was added. The resulting mixture was transferred to a 50 mL polytetrafluoroethylene-lined autoclave and stored at 200 °C for 24 h. The precipitate was then separated three times by centrifugation with ethanol and dried overnight at 60 °C (≥12 h). Finally, the mixture was crystallized at 350 °C for 3 h with a heating and cooling rate of 2 °C / min to obtain the CaF2@TiO2 nanocomposite material.

[0077] (4) Synthesis of composite nanomaterials

[0078] 20 mg of the CaF2@TiO2 nanocomposite material prepared in step (3) was added to a beaker containing a certain amount of Au NPs solution. The mixture was stirred for 60 min at 25°C in the dark. The pink precipitate was separated by centrifugation with ethanol and deionized water, and then dried at 60°C overnight (≥12 h). The final product was the composite nanomaterial (CaF2@TiO2-Au nanoparticles). The mass fraction of Au in the composite nanomaterial was 1 wt%.

[0079] Analysis example 1

[0080] Characterization analysis

[0081] The composite nanomaterials prepared in Example 1 were characterized and analyzed. Transmission electron microscopy (TEM) images and X-ray photoelectron spectroscopy (XPS) images at different scales were obtained, as shown below. Figure 1 (A) Figure 1 (B) Figure 1 (C) and Figure 1 As shown in (D).

[0082] from Figure 1 As can be seen, in the composite nanomaterial, dispersed Au nanoparticles are coated (adsorbed) in the hybrid of CaF2 (square area in the figure) and TiO2 (large irregularly shaped area in the figure) that are combined together.

[0083] Analysis example 2

[0084] Energy dispersive spectroscopy (EDS) analysis was performed on the products at each stage of the preparation process in Example 1. The results are as follows: Figure 2 As shown.

[0085] in, Figure 2 (A) is a comparison of the FTIR spectra of the oil-soluble (CaF2:Yb,Er,Tm) nanoparticles (Before) prepared in step (1) of Example 1 and the water-soluble (CaF2:Yb,Er,Tm) nanoparticles (After) prepared in step (2) of Example 1.

[0086] Figure 2 (B) is a comparison of the emission spectra of the oil-soluble (CaF2:Yb,Er,Tm) nanoparticles (Before) prepared in step (1) of Example 1 and the water-soluble (CaF2:Yb,Er,Tm) nanoparticles (After) prepared in step (2) of Example 1.

[0087] Figure 2(C) Comparison of UV-Vis-NIR absorption spectra of oil-soluble (CaF2:Yb,Er,Tm) nanoparticles (CaF2:Yb,Er,Tm) prepared in step (1) of Example 1, CaF2@TiO2 nanocomposite material (CaF2:Yb,Er,Tm@TiO2) prepared in step (3) of Example 1, and composite nanomaterial (CaF2:Yb,Er,Tm@TiO2-Au) prepared in step (4) of Example 1;

[0088] Figure 2 (D) is a comparison of the emission spectra of the oil-soluble (CaF2:Yb,Er,Tm) nanoparticles (CaF2:Yb,Er,Tm) prepared in step (1) of Example 1, the CaF2@TiO2 nanocomposite material (CaF2:Yb,Er,Tm@TiO2) prepared in step (3) of Example 1, and the composite nanomaterial (CaF2:Yb,Er,Tm@TiO2-Au) prepared in step (4) of Example 1.

[0089] from Figure 2 It can be seen that the oil-soluble (CaF2:Yb,Er,Tm) phase successfully transitioned to the aqueous phase, and there was effective energy transfer between it and TiO2 and Au. From... Figure 2 As can be seen in (D), the curves (CaF2:Yb,Er,Tm), (CaF2:Yb,Er,Tm@TiO2), and (CaF2:Yb,Er,Tm@TiO2-Au), i.e., curves a to c, show a gradual downward trend, indicating that the lifetime of photogenerated holes is extended and the photocatalytic performance is improved.

[0090] Example 2

[0091] Catalytic degradation of Rh B (Rhodamine B)

[0092] 50 mg of the composite nanomaterial prepared in Example 1 was added to 20 mL of Rh B solution (1 × 10⁻⁶). -5 Place the contents of the mixture (M) into a 100 mL quartz flask. This is used as the composite nanomaterial group (CaF2@TiO2-Au).

[0093] The same procedures were followed, except that the specific substances added to the Rh B solution were different. Specifically, a blank control group (No Catalyst) with no additives, a water-soluble (CaF2:Yb, Er, Tm) nanoparticle group (CaF2:Yb Er Tm) obtained in step (2) of Example 1, a TiO2 particle group (TiO2), and a CaF2@TiO2 nanocomposite group (CaF2@TiO2) obtained in step (3) of Example 1 were set up.

[0094] Before light irradiation, the mixtures of the above five groups were magnetically stirred in the dark for 3 hours to establish adsorption-desorption equilibrium between RhB and the catalyst. Then, while stirring, the quartz flasks were exposed to different light sources.

[0095] A 300W xenon lamp with ultraviolet, visible, and infrared filters was used to simulate the light source required for the experiment. Specifically, sunlight conditions were simulated using a 300W xenon lamp; visible light conditions were simulated using a 300W xenon lamp with a visible light cutoff filter; and ultraviolet light conditions were simulated using a 300W xenon lamp with an ultraviolet light cutoff filter.

[0096] Take 0.5 mL of the solution from the quartz flask at regular intervals and measure its absorbance.

[0097] The final absorbance measurement results are as follows: Figure 3 As shown. Figure 3 (A) is a comparison chart of absorbance measurement results for each group under ultraviolet light irradiation conditions. Figure 3 (B) is a comparison chart of absorbance measurement results under visible light conditions. Figure 3 (C) is a comparison chart of absorbance measurement results for each group under sunlight conditions (mixed illumination conditions of near-infrared, visible and ultraviolet light).

[0098] according to Figure 3 As shown, compared with the blank control group without additives (No Catalyst), the water-soluble (CaF2:Yb,Er,Tm) nanoparticle group (CaF2:YbErTm) obtained in step (2) of Example 1, the TiO2 particle group (TiO2), and the CaF2@TiO2 nanocomposite group obtained in step (3) of Example 1 (CaF2@TiO2), the prepared composite nanomaterial (CaF2@TiO2-Au) has obvious advantages in catalytic degradation of Rh B under visible light conditions.

[0099] Under ultraviolet light irradiation, visible light conditions, and sunlight conditions, the TiO2 particle group (TiO2), the CaF2@TiO2 nanocomposite material group obtained in step (3) of Example 1 (CaF2@TiO2), and the composite nanomaterial (CaF2@TiO2-Au) all showed a certain effect on the catalytic degradation of Rh B. However, the composite nanomaterial still showed the best treatment effect.

[0100] Example 3

[0101] Antibacterial performance test

[0102] Add 180 μL (1 × 10⁻⁶) to a 96-well plate 7Staphylococcus aureus culture at CFU / mL (colony forming units / mL) was then added to the wells. Subsequently, 20 μL (2 mg / mL) of the composite nanomaterial solution prepared in Example 1 was added.

[0103] A 2W, 980nm diode laser was used as the near-infrared light source. After stirring in the dark for 20 min, each well was irradiated with a 980nm laser, and 5μL of the mixed solution was dropped onto an agar plate every 5 min. This was used as the composite nanomaterial group (CaF2@TiO2-Au 1wt%).

[0104] The same operation was performed, except that the specific substances added to the pores were different. Specifically, the water-soluble (CaF2:Yb,Er,Tm) nanoparticle group (CaF2) obtained in step (2) of Example 1 and the CaF2@TiO2 nanocomposite group (CaF2@TiO2) obtained in step (3) of Example 1 were respectively set up.

[0105] All three groups were incubated at 37℃ for 18 hours, and the colony counts for each group were recorded at 0 min, 5 min, 10 min, 15 min, 20 min, and 25 min. The experimental results are as follows: Figure 4 As shown.

[0106] from Figure 4 As can be seen, the number of colonies in the composite nanomaterial group was significantly lower than that in other groups starting from 15 minutes, and the number of colonies in the composite nanomaterial group was almost invisible to the naked eye at 25 minutes.

[0107] In summary, the above-described technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing a composite nanomaterial, characterized in that, The composite nanomaterial includes X@TiO2-Au nanoparticles, wherein the X@TiO2-Au nanoparticles are X@TiO2 hybrids coated with Au nanoparticles; The X@TiO2 hybrid is composed of water-soluble (X: Yb, Er, Tm) nanoparticles and TiO2 nanoparticles. X is a visible light absorbing material, and X is CaF2; Including the following steps: Provides oil-soluble (X:Yb, Er, Tm) nanoparticles; A ligand exchange reagent was prepared by mixing ethanol, chloroform, and 0.2 M sodium citrate solution in a volume ratio of 1:1:

1. The oil-soluble (X:Yb,Er,Tm) nanoparticles were stirred with the ligand exchange reagent at room temperature for >12h to obtain water-soluble (X:Yb,Er,Tm) nanoparticles. The water-soluble (X:Yb,Er,Tm) nanoparticles were mixed with diethylenetriamine, and tetrabutyl titanate was added. The mixture was reacted at 150-250°C for 20-40 h and then separated to obtain X@TiO2 nanocomposite material. The X@TiO2 nanocomposite material was mixed with an aqueous solution of Au nanoparticles and stirred and reacted in the dark at 20-30°C for 40-80 minutes to obtain the composite nanomaterial.

2. The production method according to claim 1, characterized by, The oil-soluble (X:Yb,Er,Tm) nanoparticles are obtained by mixing calcium salt with ytterbium salt, erbium salt, thulium salt and NH4F stock solution to obtain a reaction mixture; Prepare a mixture including NaOH, ethanol, deionized water and oleic acid; The reaction mixture is mixed with the liquid mixture and heated at 170-190°C for 30-50 hours to obtain the oil-soluble (X:Yb,Er,Tm) nanoparticles.

3. The preparation method according to claim 1, characterized in that, The process of stirring at room temperature for more than 12 hours is followed by centrifugation purification of the stirred product using a combination of water and ethanol solvents.

4. The preparation method according to claim 3, characterized in that, The centrifugation purification speed is 9000~12000 rpm; the centrifugation purification time is 8~12 min.

5. The preparation method according to claim 1, characterized in that, The separation process includes, in sequence, ethanol centrifugation, drying, and crystallization.

6. The preparation method according to claim 5, characterized in that, The crystallization treatment temperature is 300~400℃; the crystallization treatment duration is 2.5~3.5h.

7. An application of a composite nanomaterial prepared by the preparation method according to any one of claims 1 to 6, characterized in that, The composite nanomaterials were mixed with a solution of the organic matter to be degraded under dark conditions to obtain a mixture. The mixture is exposed to light to degrade the organic matter to be degraded. The illumination conditions include one or more of near-infrared light illumination conditions, visible light illumination conditions, and ultraviolet light illumination conditions.

8. An application of a composite nanomaterial prepared by the preparation method according to any one of claims 1 to 6, characterized in that, Under dark conditions, the composite nanomaterials were added to the bacterial solution and mixed to obtain a mixture. The mixture is irradiated with one or more of near-infrared light, visible light, and ultraviolet light to inhibit bacterial growth.

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