A copper-cerium-titanium nanoscale photocatalytic material for synergistic degradation of vocs and microbial disinfection, and a preparation method and application thereof

Abstract

The application provides a copper-cerium-titanium nanoscale photocatalytic material for synergistic VOCs degradation and microbial disinfection, a preparation method and application thereof, and relates to the technical field of ultraviolet photocatalytic disinfection. x Cu y Ti z O w , wherein x is 0.5-20, y is 0.5-10, x+y+z=100, and w=2x+y+2z. The preparation method comprises the following steps: dissolving the precursors of Ce, Cu and Ti in an organic solvent, spraying pyrolysis in a high-pressure oxygen flame, atomizing the above-mentioned dissolving matter into an aerosol, and agglomerating to form a metal oxide; under the action of combustion gas thermal force, the formed metal oxide is adsorbed on the surface of a stagnation plate, and after cooling, the copper-cerium-titanium nanoscale photocatalytic material is obtained. The material can not only effectively disinfect and purify pathogenic microorganisms on the surface of air and the catalyst glass plate through ultraviolet light, but also can photocatalytically degrade organic matters contained in the air, has a double purification mechanism, and can achieve the effect of synergistic disinfection and VOCs degradation on air.

Description

Technical Field

[0001] This invention relates to the field of ultraviolet photocatalytic disinfection technology, and in particular to a copper-cerium-titanium nanoscale photocatalytic material that synergistically degrades VOCs and disinfects microorganisms, as well as its preparation method and application. Background Technology

[0003] Ultraviolet (UV) light, as a highly efficient, safe, and pollution-free disinfection method, has become an ideal environmental governance technology for the catalytic degradation of VOCs. Therefore, UV disinfection combined with photocatalytic degradation of VOCs is an air treatment technology that satisfies both synergistic air disinfection and efficient VOCs degradation. TiO2 is a common photocatalyst. Under UV irradiation, electrons in the valence band of TiO2 transition to the conduction band, forming electron-hole pairs. Most of the generated electron-hole pairs recombine on the surface or in the bulk within a very short time (ns), dissipating as heat and light energy. Only a small portion of electron-hole pairs transfer to the semiconductor surface to continue participating in the reaction. The potential energy of photogenerated holes reaches over 3.0 eV. In addition, positively charged holes react with OH groups adsorbed on the catalyst surface... - It reacts with H2O to generate hydroxyl radicals. Hydroxyl radicals are a more reactive oxygen species and are generally considered to be the main active substances in photocatalytic reactions. Photogenerated electrons can also react with O2 to generate O2. - Reactive oxygen species such as hydroxyl radicals and superoxide radicals are highly reactive; formaldehyde reacts with them to form the intermediate product HCOOH, which is ultimately oxidized to CO2 and water. TiO2 is a classic photocatalytic material, considered a promising green material for pollutant purification due to its stable chemical properties, low cost, environmental friendliness, and safety. Modified photocatalytic materials based on TiO2 have always been a research hotspot in the field of catalysis.

[0004] Morphology and bandgap modulation are common modification methods for photocatalytic materials. The morphological and structural characteristics of TiO2 include size, specific surface area, crystal form, and exposed crystal faces. These characteristics affect the crystal structure of the catalyst and the number and types of active sites, thus influencing catalytic activity. Researchers optimize synthesis strategies and leverage solid-state surface science to understand surface catalysis mechanisms at the molecular and atomic levels and construct catalyst morphology-structure-performance relationships. Bandgap modulation strategies mainly include metal ion doping, non-metal ion doping, and multi-element co-doping. Doping introduces intermediate energy levels into the semiconductor bandgap, thereby affecting the separation, migration, recombination / conversion processes of charge carriers, improving the spectral absorption range and charge carrier separation efficiency of photocatalytic materials, and enhancing their photocatalytic performance. Metal element doping mainly includes rare earth metals (Ce, La, etc.) and transition metals (Mn, Fe, Cu, etc.). Sun et al. used Fe...3+ Replacing part of the Ti in the TiO2 lattice 4+ The doped Fe-TiO2 exhibits significantly increased specific surface area and pore volume, and possesses visible light photocatalytic activity. As the Fe / Ti atomic molar ratio increases from 0.1% to 1.5%, the toluene degradation activity of Fe-TiO2 first increases and then decreases, with the optimal doping ratio being 0.7%. Similar doping modifications have been applied to indoor formaldehyde. Li et al. doped Fe into TiO2, broadening the photoresponse range while improving carrier separation efficiency and increasing the number of surface hydroxyl radicals and superoxide radicals, thus demonstrating better formaldehyde degradation activity. Summary of the Invention

[0005] To address the aforementioned issues, this invention employs a UVC (200-400nm) wavelength ultraviolet light source and flame synthesis of copper-cerium-titanium catalysts to achieve air disinfection and VOCs degradation. Specifically, the preparation method involves using flame jetting to adjust the lattice, size, and hole ratio of CuO, CeO, and TiO2, promoting the introduction of intermediate energy levels, thereby affecting the separation, migration, recombination / conversion processes of charge carriers. This improves the spectral absorption range and charge carrier separation efficiency of the photocatalytic material, enhances its photocatalytic performance, and increases both air disinfection efficiency and VOCs degradation efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A copper-cerium-titanium nanoscale photocatalytic material with synergistic VOCs degradation and microbial disinfection, its chemical formula is Ce x Cu y Ti z O w Where x is the mole fraction of Ce in the material, y is the mole fraction of Cu, z is the mole fraction of Ti, and w is the mole fraction of O. x ranges from 0.5 to 20, y ranges from 0.5 to 10, and x + y + z = 100. The mole fraction of oxygen cannot be measured. Oxygen combines with the aforementioned Ce, Cu, and Ti elements to form a stable oxide, the theoretical value of which is w = 2x + y + 2z.

[0007] Preferably, x is 0.5-15 and y is 0.5-10; more preferably, both x and y are 5.

[0008] Preferably, the particle size of the photocatalytic material is 5-50 nm, and more preferably 8-25 nm.

[0009] This invention also provides a method for preparing the copper-cerium-titanium nanoscale photocatalytic material, comprising the following steps: S1. The precursors of Ce, Cu and Ti are dissolved in an organic solvent and pyrolyzed in a high-pressure oxygen flame. The dissolved substances are atomized into aerosols. Under high-temperature flame conditions, the aerosols are heated, burned, evaporated, precipitated, and aggregated to form metal oxides. S2. Under the action of the thermophoretic force of the combustion gas flow, the metal oxide formed in S1 is adsorbed on the surface of the stagnation plate, and the collected metal oxide is rapidly cooled to obtain the copper-cerium-titanium nanoscale photocatalytic material.

[0010] Preferably, in step S1, the organic solvent is a mixture of ethanol and octane in a volume ratio of 1:1. The organic solvent serves not only as a solvent but also as fuel for jet pyrolysis. Pure oxygen is used as the atomizing gas.

[0011] Preferably, in S1, the Ce precursor is cerium nitrate, the Cu precursor is copper carbonyl, and the Ti precursor is diisopropyl di(acetylacetonyl)titanate. After combustion, the above precursors respectively form CeO2 and CuO as catalyst doping components, with TiO2 serving as the support.

[0012] Preferably, in S1, the proportion of Ce atoms in the precursor metal elements is 0.5%-20%; the proportion of Cu atoms is 0.5%-10%, and the total atomic percentage of Ce, Cu and Ti is 100%.

[0013] Preferably, in step S1, the precursors of Ce, Cu, and Ti are first mixed according to the atomic content of the target photocatalytic material, and then the mixture is dissolved in an organic solvent. The preferred dissolution conditions are ultrasonic treatment for 20-30 minutes to ensure complete dissolution of the solid precursors in the organic solvent. The ratio of the total amount of Ce, Cu, and Ti precursors to the amount of organic solvent is (1g):(15-30ml), preferably 1g:20ml.

[0014] Preferably, in S1, the flow rate of the high-pressure oxygen is 8-15 L·min. -1 10L·min is preferred -1 The oxygen pressure is 0.4-0.5 MPa. The diameter of the formed aerosol is 500-1000 nm.

[0015] Preferably, in S2, when a temperature gradient exists in the gas, suspended particles tend to move from the high-temperature region to the low-temperature region; the force that produces this effect is called thermophoretic force. The stabilizing plate is an aluminum plate with a thickness of 1-5 mm, and a water-cooling device is provided below the stabilizing plate to control the temperature of the stabilizing plate below 50°C, so as to rapidly cool the collected photocatalytic material.

[0016] Nano-TiO2 exhibits good photocatalytic performance, but its band gap is too wide (3.0 eV), limiting its absorption to ultraviolet light with wavelengths less than 400 nm. To improve its response in the visible light range, researchers have modulated the band structure of TiO2 through doping, defect engineering, and heterostructure construction. This invention uses cerium and copper as doping metals to further reduce the band gap to 1.9 eV, improving the catalyst's utilization efficiency of the light source and promoting its catalytic efficiency. During flame synthesis, the cerium and copper doped precursors have pyrolysis temperatures close to those of the TiO2 precursor. During oxidation nucleation, the metal oxides are inter-doped and coupled, forming a copper-cerium doped TiO2 photocatalytic material. This material possesses the defect properties of TiO2, including oxygen vacancies (V_O), titanium vacancies (V_Ti), and interstitial atoms (Cu and Ce). These defects can introduce impurity energy levels, thereby altering the band structure of TiO2 and significantly impacting its electronic structure and photocatalytic performance.

[0017] The present invention also provides a method for preparing a coating using the aforementioned photocatalytic material, comprising the following steps: (1) Disperse 5-10g of the photocatalytic material in 100ml of anhydrous ethanol and stir at room temperature for 0.5-2h to make the photocatalytic material uniformly dispersed in ethanol to form a suspension; (2) Dissolve 5g of waterborne polyurethane in 100ml of anhydrous ethanol and stir at 70℃ for 1h to uniformly disperse the waterborne polyurethane in the ethanol suspension to obtain a suspension of waterborne polyurethane. (3) Spray a uniform layer of waterborne polyurethane suspension obtained in step (2) onto the surface of a glass slide with a length and width of 50×50mm. After standing for 4 hours, spray another layer of photocatalytic material suspension obtained in step (1) to obtain a photocatalytic material coating. (4) Let the photocatalytic material coating obtained in step (3) stand at room temperature for 20-60 min, and then dry it in a drying oven at 100℃ for 1-2 h to obtain the catalyst coating.

[0018] The present invention also provides the application of the photocatalytic material in the degradation of VOCs and in the elimination of pathogenic microorganisms.

[0019] The beneficial effects of the technical solution provided by this invention include at least the following: This invention provides a copper-cerium-titanium nanoscale photocatalytic material that can perform photocatalysis under ultraviolet light, synergistically treating airborne bacteria and degrading VOCs. This invention not only effectively disinfects and purifies air and pathogenic microorganisms on the surface of the catalyst glass plate using ultraviolet light, but also photocatalytically degrades organic matter in the air, possessing a dual purification mechanism that achieves synergistic disinfection and VOCs degradation of air. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the preparation method of the copper-cerium-titanium nanoscale photocatalytic material of the present invention; Figure 2 This is a schematic diagram of the UV + photocatalytic VOCs degradation and disinfection system of the present invention; Figure 3 The effect of Ce loading content on VOCs degradation efficiency in photocatalytic materials (organic matter concentration 50 ppm, carrier gas is air). Figure 4 The effect of Cu loading content on VOCs degradation efficiency in photocatalytic materials (organic matter concentration 50 ppm, carrier gas is air). Figure 5 TEM image of photocatalytic material; Figure 6 XRD pattern of photocatalytic material; Figure 7 XPS analysis of Ce-based photocatalytic materials. Detailed Implementation

[0022] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0023] Figure 1 This is a schematic diagram of the preparation method of the copper-cerium-titanium nanoscale photocatalytic material of the present invention. An organic solvent containing precursors of Ce, Cu, and Ti is injected into an atomizer using a syringe. Under high-pressure oxygen conditions, the organic solution of the precursors is atomized into an aerosol of 500-1000 nm. Under high-temperature flame conditions, the aerosol is heated, burned, evaporated, and the solute precipitates and aggregates to form metal oxides. The formed oxides are adsorbed onto the surface of a stabilizing plate by the hot gas flow. Cooling water circulates inside the stabilizing plate, rapidly cooling the collected metal oxides to obtain the copper-cerium-titanium nanoscale photocatalytic material.

[0024] Example

[0025] (1) A mixture of ethanol and octane in a volume ratio of 1:1 is used as the organic solvent and fuel, and pure oxygen is used as the atomizing gas; (2) Cerium nitrate was used as the Ce precursor, copper carbonyl as the Cu precursor, and diisopropyl di(acetylacetonyl)titanate as the Ti precursor. By changing the ratio of the above precursors, the Ce atom content in the synthesized copper-cerium-titanium nanoscale photocatalytic material was 0.5%-20%, the Cu atom content was 0.5%-10%, and the Ti atom content ranged from 70%-99.2%.

[0026] (3) The above-mentioned precursors cerium nitrate, copper carbonyl, and diisopropyl di(acetylacetonyl)titanate are mixed according to the atomic content of the target photocatalytic material, and then dissolved in the organic solvent obtained in step (1). The ratio of the amount of precursor solid to the amount of organic solvent is 1 g: 20 ml. The above solid-liquid mixture is ultrasonically treated for 20 min to ensure that the solid precursor is completely dissolved in the organic solvent; (4) Flame jet pyrolysis synthesis: at an oxygen flow rate of 10 L·min -1 Under high-pressure oxygen conditions of 0.4-0.5 MPa, the solution obtained in step (3) is atomized into aerosols with a particle size of 500-1000 nm. Under high-temperature flame conditions, the aerosols are heated, burned, evaporated, precipitated, and aggregated to form metal oxides.

[0027] (5) Under the action of hot air flow, the metal oxide formed after combustion in step (4) is adsorbed on the surface of the stagnation plate (aluminum plate with a thickness of 1 mm). The stagnation plate is equipped with a water cooling device to ensure that the temperature of the stagnation plate is below 50°C, so that the collected metal oxide is rapidly cooled to obtain the copper cerium titanium nanoscale photocatalytic material.

[0028] (6) After the reaction is complete, the photocatalytic material on the stagnant plate is collected for use in the mercury oxidation experiment. The precursor ratio and the number of the formed photocatalytic material are listed in Table 1.

[0029] Table 1. Precursor ratios and the number of photocatalyst materials formed.

[0030] The photocatalytic materials prepared in Table 1 above were respectively fabricated into coatings for subsequent catalyst testing. The coating preparation included the following steps: (1) Disperse 5g of the photocatalytic material in 100ml of anhydrous ethanol and stir at room temperature for 1h to make the photocatalytic material uniformly dispersed in ethanol to form a suspension; (2) Dissolve 5g of waterborne polyurethane in 100ml of anhydrous ethanol and stir at 70℃ for 1h to uniformly disperse the waterborne polyurethane in the ethanol suspension to obtain a suspension of waterborne polyurethane. (3) Spray a uniform layer of waterborne polyurethane suspension obtained in step (2) onto the surface of a glass slide with a length and width of 50×50mm. After standing for 4 hours, spray another layer of photocatalytic material suspension obtained in step (1) to obtain a photocatalytic material coating. (4) The photocatalytic material coating obtained in step (3) was left to stand at room temperature for 30 min, and then dried in a drying oven at 100°C for 1 h to obtain coatings of different photocatalytic materials.

[0031] The coatings of the different photocatalytic materials mentioned above were tested using the following methods: 1. VOCs degradation test: Simulated flue gas containing 50 ppm of organic compounds such as chlorobenzene and toluene was introduced into the photocatalyst reaction system. The residence time of the simulated flue gas in the reaction system was 1-5 min to evaluate the degradation effect of the ultraviolet catalyst on organic compounds. 2. Pathogenic microorganism elimination efficacy test: The test strains were: Escherichia coli (8099, 6th generation), Staphylococcus aureus (ATCC6538, 6th generation), Candida albicans (ATCC10231, 4th generation), and poliovirus. All of the above strains were purchased from the China General Microbiological Culture Collection Center.

[0032] (1) Bacterial disinfection: Bacteriological equipment: Biosafety cabinet (ESCO CLASS II BSC), constant temperature incubator (MMM incucell222L), constant temperature water bath (Julabo SW22), turbidimeter, timer.

[0033] Reagents and consumables: The following culture media were used for different bacteria: tryptone soy agar (TSA) for Escherichia coli and Staphylococcus aureus, and Saburg agar for Candida albicans. All the above culture media were purchased from Beijing Luqiao. The diluent was 0.03M PBS (pH 7.2), the organic interfering agent was 0.3% BSA solution (Sigma), and the carrier was a quartz glass slide (50mm × 50mm).

[0034] The experimental method is as follows: Standard: GB 28235-2020 Appendix G "Laboratory Microbial Killing Test for Disinfection of Object Surfaces".

[0035] Preparation of bacterial suspension: Take freshly cultured bacterial slant agar plates (18-24 hours), scrape off the bacterial growth with sterile PBS, and prepare a bacterial suspension (1×10⁻⁶). 8 ~5×10 8 CFU / mL). Mix the bacterial suspension with 0.3% BSA at a 1:1 ratio, inoculate onto glass slides using the drop staining method (10 μL / slide), spread evenly, and dry at 37°C for 20-30 min (or air dry at room temperature).

[0036] Bacterial count recovered from bacterial tablets: Bacteria (Escherichia coli, Staphylococcus aureus): 1×10⁻⁶ 6 ~5×10 6 CFU / tablet, fungus (Candida albicans): 1×10 5 ~5×10 5 CFU / tablet (Bacterial suspension and tablets are prepared and used on the same day.)

[0037] Quantitative sterilization test: Environmental conditions: Bacterial test: temperature 24~26℃, humidity 17%; temperature 23~24℃, humidity 14%. Irradiation distance: 20 cm (20 cm below the light source); irradiate Escherichia coli / Staphylococcus aureus for 10 s, and irradiate Candida albicans for 5 s, 10 s, 20 s, and 30 s respectively, to conduct multi-gradient tests.

[0038] Repeated design: Each experiment was repeated 3 times independently.

[0039] (2) Virus disinfection: Test virus strain: Poliovirus type 1 vaccine strain (PV-1 / Sabin / 2003), preserved in our laboratory.

[0040] Experimental cell line: VERO cells.

[0041] Reagents and consumables: DMEM culture medium (containing 10% FBS: Gibco 10270-106), organic interfering agents (0.3% BSA or 3% BSA; BSA, bovine serum albumin, Sigma); carrier: quartz glass slides, 50mm × 50mm in size, defatted and sterilized.

[0042] The experimental method is as follows: Basis: Appendix G of GB 28235-2020 "Hygienic Requirements for Ultraviolet Sterilizers" "Laboratory Microbial Killing Test for Object Surface Disinfection"; Appendix CC of GB 17988-2008 "Safety and Hygiene Requirements for Food Utensil Sterilizers"; Article 2.1.1.10 of the Ministry of Health's "Disinfection Technical Specifications" (2002 Edition).

[0043] Preparation of virus suspension: PV-1 virus suspension was diluted 1:1 with an organic interfering agent containing 0.3% bovine serum albumin or 3% bovine serum albumin for later use, and virus slides were prepared.

[0044] Virus inactivation test: Figure 2This is a schematic diagram of the UV + photocatalytic VOCs degradation and disinfection system of the present invention. Glass slides with coatings containing different photocatalytic materials are placed between opposing UV disinfection light sources. According to the instructions, the UV disinfection light source irradiates the PV-1 virus on the carrier slide for 10 seconds at a distance of 20 cm. The laboratory environment was 21°C and 20% humidity. The experiment was repeated three times.

[0045] After the coating tests of the different photocatalytic materials were completed, the following methods were used for characterization: 1. Screening of VOCs degradation effects This invention investigates the effect of Ce element loading on photocatalytic materials. The effect of TiO2 catalyst alone on VOCs degradation ranges from 69.2% to 72.1%. Figure 3 The effect of Ce loading content on VOCs degradation efficiency in photocatalytic materials is shown. Figure 3 As shown, the addition of Ce significantly improved the degradation efficiency of photocatalysts for benzene, chlorobenzene, and toluene. The Ce5Ti catalyst achieved the best degradation efficiency, with reductions of 88.7%, 83.3%, and 85.6% for benzene, chlorobenzene, and toluene, respectively. With further increases in Ce loading, the degradation efficiency of the catalyst for VOCs decreased. Therefore, a Ce loading of 5% was selected.

[0046] This invention also explores the effects of multi-element mixed doping on photocatalytic materials. Figure 4 The effect of Cu loading content on VOCs degradation efficiency in photocatalytic materials is shown. Figure 4 As shown, the addition of Cu further improved the degradation efficiency of the photocatalytic material for benzene, chlorobenzene, and toluene. The Ce5Cu5Ti catalyst achieved the best degradation efficiency, with degradation efficiencies of 94.6%, 89.3%, and 89.5% for benzene, chlorobenzene, and toluene, respectively. With further increases in Cu loading, the catalyst's VOCs degradation efficiency decreased. Therefore, the Ce5Cu5Ti catalyst achieved the best photocatalytic effect.

[0047] 2. The selected Ce5Cu5Ti catalyst was tested for its effectiveness in eliminating pathogenic microorganisms.

[0048] (1) Escherichia coli bactericidal test

[0049] Under the experimental conditions, the handheld high-energy pulsed ultraviolet sterilizer was applied to Escherichia coli for 10 seconds at a distance of 10 cm from the lower edge of the handle (irradiation distance was 20 cm). The test was repeated three times. The average log reduction value was >6.22, and the log reduction value in each test was >3.00, which met the judgment criteria of the "Hygienic Requirements for Ultraviolet Sterilizers" and was judged as qualified for sterilization. The results of the Escherichia coli sterilization test are shown in Table 2.

[0050] Table 2 Results of Escherichia coli bactericidal test

[0051] Note: No bacterial growth was observed in the negative control group.

[0052] (2) Sterilization test for Staphylococcus aureus

[0053] Under the experimental conditions, the handheld high-energy pulsed ultraviolet sterilizer irradiated Staphylococcus aureus on a glass slide for 10 seconds at a distance of 10 cm from the lower edge of the handle (irradiation distance was 20 cm). The average log reduction value was 4.57, and the log reduction values ​​for each test were all greater than 3.00, meeting the criteria for disinfection according to the "Hygienic Requirements for Ultraviolet Sterilizers". The sterilization effect of the handheld high-energy pulsed ultraviolet sterilizer on Staphylococcus aureus is shown in Table 3.

[0054] Table 3. Killing effect of handheld high-energy pulsed ultraviolet sterilizer on Staphylococcus aureus

[0055] Note: No bacterial growth was observed in the negative control group.

[0056] (3) Candida albicans bactericidal test

[0057] Under the experimental conditions, a handheld high-energy pulsed ultraviolet sterilizer, positioned 10 cm from the lower edge of the handle (irradiation distance 20 cm), effectively killed Candida albicans on a glass slide by irradiating it for more than 20 seconds. See Table 4.

[0058] Table 4. Killing effect of handheld high-energy pulsed ultraviolet sterilizer on Candida albicans

[0059] Note: No bacterial growth was observed in the negative control group.

[0060] (4) Inactivation effect test of poliovirus

[0061] Under the experimental conditions, the handheld high-energy pulsed ultraviolet sterilizer irradiated the poliovirus on the slide for 10 seconds, with the slide 10 cm from the lower edge of the handle (irradiation distance 20 cm). The test was repeated three times, and the logarithmic value of inactivation in each test was ≥4.00, meeting the judgment criteria of the "Hygienic Requirements for Ultraviolet Sterilizers". Therefore, the test was deemed qualified for laboratory disinfection of poliovirus contaminants. See Table 5.

[0062] Table 5. Inactivation test of poliovirus by handheld high-energy pulsed ultraviolet sterilizer.

[0063] Note: The negative control group was uncontaminated and showed good cell growth.

[0064] 3. TEM analysis

[0065] The elemental crystal morphology of different catalyst surfaces was analyzed using TEM, and the results are shown in the figure. Figure 5 .like Figure 5 As shown in (a), the catalyst support TiO2 mainly exists in a cubic morphology. Figure 5 (b) and Figure 5 As shown in (c), CeO2 on the surface of the Ce5Ti catalyst exists in the (111) crystal form with a lattice spacing of 0.31 nm, consistent with the XRD analysis results. Figure 5 As shown in (d), CuO (110) lattice fringes with a spacing of 0.28 nm and CeO2 (111) lattice fringes with a spacing of 0.31 nm appear on the surface of the Cu5Ce5Ti catalyst, forming a doped crystal interface between CuO and CeO2. At the interface, atoms in CuO and CeO crystals are mutually substituted, forming crystal dislocations, and the crystal fringe boundaries are twisted and transferred, promoting the formation of a large amount of Cu. + and Ce 3+ This process creates oxygen vacancies on the catalyst surface, thereby enhancing the catalyst's oxygen storage and redox capabilities.

[0066] 4. XRD Analysis

[0067] The crystal phases of different catalysts were analyzed using XRD technology, and the results are as follows: Figure 6 As shown. The XRD patterns of the three catalysts mainly exhibit characteristic peaks of anatase and rutile TiO2 morphologies (JCPDS 21-1272). The three catalysts at 2... θ A weak CeO2 crystal peak appears at 28.35°, indicating that Ce is highly dispersed on the support surface and possesses high catalytic oxidation activity. The catalyst at 35.5°... o and 38.6 o The presence of a weak CuO (111) characteristic peak (JCPDS 48-1548) at the position indicates that the majority of the Cu active component is uniformly distributed on the catalyst surface. Based on these results, it is evident that Ce and Cu elements are highly uniformly dispersed on the support surface.

[0068] 5. XPS Analysis

[0069] This invention uses XPS technology to analyze the valence states of various elements on the catalyst surface. For example... Figure 7 As shown in (a), the Ce element energy spectrum contains 8 peaks: u 0、 u 1. u 2. u 3. v 0、v 1. v 2 and v 3. Among them u 1 and v 1 represents Ce 3+ ; u 0、 u 2. u 3. v 0、 v 2 and v 3 represents Ce 4+ Ce 3+ Generally used as oxygen vacancies or adsorption sites. Ce5Ti catalyst Ce 3+ Peak area and Ce 4+ Peak area ratio (Ce) 3+ / Ce 4 + The Ce content of Cu5Ce5Ti is 31.2%. 3+ / Ce 4+ The area ratio increased to 39.2%. This result is consistent with the TEM analysis, indicating that CuO and CeO2 doping forms crystal dislocations, resulting in the formation of more Ce. 3+ And oxygen vacancies.

[0070] like Figure 7 As shown in (b), the two characteristic peaks of O element on the surface of Ce5Ti and Cu5Ce5Ti catalysts are: the characteristic peak at 529.9-530.0 eV represents lattice oxygen, and the characteristic peak at 530.8-531.0 eV represents active oxygen. Active oxygen is generally highly active adsorbed oxygen adsorbed at oxygen vacancies, and is a key active site for VOCs oxidation. The area ratio of active oxygen characteristic peaks in Ce5Ti catalyst is 38.7%, and that in Cu5Ce5Ti catalyst is 45.8%. This result is consistent with that of Ce5Ti catalyst. 3+ / Ce 4+ The area ratio increased consistently. For example... Figure 7 As shown in (c), the two main characteristic peaks on the surface of the Cu5Ce5Ti catalyst at 932.5 eV and 934.2 eV represent Cu, respectively. + And CuO. On the surface of the Cu5Ce5Ti catalyst, Cu mainly exists as CuO. + The form exists, which is consistent with the oxygen vacancy interface formed by Cu and Ce atom doping. Cu before and after the reaction of the Cu5Ce5Ti catalyst. + The CuO ratio decreased from 69.4% to 57.2%, which may be partly due to Cu + The reactive oxygen species formed react with chlorobenzene to form a large amount of CuCl2, therefore, Cu 2+ The proportion has increased significantly. For example... Figure 7 As shown in (d), the Ce of Cu5Ce5Ti 3+ / Ce4+ The area ratio decreased from 39.2% before the reaction to 35.4% after the reaction, indicating that some Ce... 3+ The active site is converted into a stable Ce during the reaction. 4+ This reduces the catalyst's oxygen absorption and release capacity. For example... Figure 7 As shown in (e), the two characteristic peaks of O on the surface of the Cu5Ce5Ti catalyst changed significantly before and after the reaction. The area ratio of the active oxygen characteristic peak of the Cu5Ce5Ti catalyst decreased from 45.8% before the reaction to 35.3% after the reaction, indicating that a large amount of active oxygen participated in the VOCs oxidation reaction.

[0071] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A copper-cerium-titanium nanoscale photocatalytic material for synergistic VOCs degradation and microbial disinfection, characterized in that, The chemical formula of the material is Ce. x Cu y Ti z O w , where x is 0.5-20, y is 0.5-10, x+y+z=100; w=2x+y+2z.

2. The copper-cerium-titanium nanoscale photocatalytic material according to claim 1, characterized in that, x is 0.5-15, y is 0.5-10, and preferably both x and y are 5.

3. The preparation method of the copper-cerium-titanium nanoscale photocatalytic material according to claim 1 or 2, characterized in that, Includes the following steps: S1. The precursors of Ce, Cu and Ti are dissolved in an organic solvent and pyrolyzed in a high-pressure oxygen flame. The dissolved substances are atomized into aerosols. Under high-temperature flame conditions, the aerosols are heated, burned, evaporated, precipitated, and aggregated to form metal oxides. S2. Under the action of thermophoretic force of combustion gas flow, the metal oxide formed in S1 is adsorbed on the surface of the stagnation plate, and after cooling, the copper-cerium-titanium nanoscale photocatalytic material is obtained.

4. The preparation method of the copper-cerium-titanium nanoscale photocatalytic material according to claim 3, characterized in that, In S1, the organic solvent is a mixture of ethanol and octane in a volume ratio of 1:1, and pure oxygen is used as the atomizing gas.

5. The preparation method of the copper-cerium-titanium nanoscale photocatalytic material according to claim 3, characterized in that, In S1, the Ce precursor is cerium nitrate, the Cu precursor is copper carbonyl, and the Ti precursor is diisopropyl di(acetylacetonyl)titanate.

6. The preparation method of the copper-cerium-titanium nanoscale photocatalytic material according to claim 3, characterized in that, In S1, the proportion of Ce atoms in the precursor metal elements is 0.5%-20%; the proportion of Cu atoms is 0.5%-10%, and the total atomic percentage of Ce, Cu and Ti is 100%.

7. The method for preparing the copper-cerium-titanium nanoscale photocatalytic material according to claim 3, characterized in that, In S1, the precursors of Ce, Cu and Ti are first mixed according to the atomic content of the target photocatalytic material, and then the mixture is dissolved in an organic solvent; the ratio of the total amount of the precursors of Ce, Cu and Ti to the amount of organic solvent is (1g):(15-30ml), preferably 1g:20ml.

8. The method for preparing the copper-cerium-titanium nanoscale photocatalytic material according to claim 3, characterized in that, In S1, the flow rate of the high-pressure oxygen is 8-15 L·min. -1 The oxygen pressure is 0.4-0.5 MPa, and the diameter of the formed aerosol is 500-1000 nm.

9. The method for preparing the copper-cerium-titanium nanoscale photocatalytic material according to claim 3, characterized in that, In S2, the stop plate is an aluminum plate with a thickness of 1-5mm, and a water cooling device is installed below the stop plate to control the temperature of the stop plate below 50℃.

10. The application of the photocatalytic material according to claim 1 or 2 and the photocatalytic material prepared by the method according to any one of claims 3 to 9 in the degradation of VOCs and in the elimination of pathogenic microorganisms.

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