A TiO 2 -WO 3 -Co 3 O 4 Composite nano-array catalytic material and its preparation method and application

Abstract

The present invention discloses a TiO2-WO3-Co3O4 composite nanoarray catalytic material, its preparation method and application, belonging to the technical field of catalysts; the method uses conductive glass as the substrate, water, hydrochloric acid and titanium source as raw materials, and prepares TiO2 nanoarrays supported on conductive glass by hydrothermal method; then, using TiO2 as the substrate, water, hydrochloric acid solution, oxalic acid and tungsten source as raw materials, TiO2-WO3 composite nanoarrays are synthesized by hydrothermal method; finally, using TiO2-WO3 nanoarrays as the substrate, ethanol and cobalt source as raw materials, a TiO2-WO3-Co3O4 photothermal composite nanoarray material is prepared by solvothermal method; applying this catalyst to the photocatalytic oxidation reaction of cyclohexane greatly improves its conversion rate and selectivity; finally, immobilizing the catalyst on glass can greatly reduce the separation process of subsequent reactions and reduce costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts and particularly relates to a TiO 2 -WO 3 -Co 3 O 4 Composite nano-array catalytic material and its preparation method and application. Background Art

[0002] In the petroleum industry, the oxidation reaction of cyclohexane is a very important reaction. Its oxidation products are cyclohexanone and cyclohexanol (collectively known as KA oil). KA oil is one of the raw materials for the production of nylon 6 and nylon 66, which have long been widely used in pillar industries such as engineering plastics, new energy vehicles and aerospace. The traditional cyclohexane oxidation industrial route is mainly a thermal catalytic reaction or a non-catalytic reaction carried out under high temperature and pressure, which has the disadvantages of low conversion rate (4% to 6%), poor selectivity and high energy consumption. On the other hand, since the catalyst is difficult to separate, it is very easy to slag in the pipeline, block the pipeline, affect the normal operation of the reaction, and the cleaning cost is very high.

[0003] In response to the problem of low conversion rate, emerging photocatalysts in recent years can improve product conversion by adjusting the energy band position of semiconductors, such as the composite semiconductor catalysts in patents CN112473657A and CN105126892A. However, the former has poor dispersibility and thermal stability as a catalyst powder, and is very easy to agglomerate in the reaction channel, making it difficult to efficiently utilize the spectrum; the latter, as a carbon nanofiber structure, has weak impact resistance, is easy to break, and loses its efficient catalytic activity.

[0004] Nano-array catalysts are a better way to solve the above problems. Nano-array catalysts are mainly used in the field of photoelectric catalytic solar cells because their substrate conductive glass has good conductivity and is conducive to electron transmission. In the field of catalytic degradation of organic matter, their catalyst structure still has advantages, with a unique light trapping effect, which can improve the utilization efficiency of sunlight and also has excellent heat storage performance. Summary of the invention

[0005] In view of the problems existing in the prior art, the first purpose of the present invention is to provide a composite photothermal nanoarray catalytic material. The catalyst forms a heterostructure by compounding photocatalytic semiconductors and thermal catalytic semiconductors with different morphologies on a nanoarray. The heterojunction can reduce the recombination rate of photogenerated holes and electrons, while increasing the contact area between the catalyst and the reactants, improving the catalytic activity, and solving the problem of low reaction conversion rate. At the same time, the glass-loaded nanoarray also solves the problem of difficulty in separating the reaction products and powdered catalysts.

[0006] The first object of the present invention is to provide a TiO 2 -WO3 -Co 3 O 4 A method for preparing composite nanoarray catalytic materials.

[0007] The second object of the present invention is to provide TiO 2 -WO 3 -Co 3 O 4 Composite nanoarray catalytic materials.

[0008] The third object of the present invention is to improve the TiO 2 -WO 3 -Co 3 O 4 Application of composite nanoarray catalytic materials in catalytic cyclohexane oxidation.

[0009] To this end, the first technical solution provided by the present invention is as follows:

[0010] A TiO 2 -WO 3 -Co 3 O 4 The preparation method of the composite nano-array catalytic material comprises the following steps in sequence:

[0011] S1. Preparation of TiO 2 Nanoarray:

[0012] Add titanium source to deionized water, and use hydrochloric acid to adjust the pH of the solution to acidic. Place the cleaned conductive glass obliquely into the prepared precursor solution and perform hydrothermal reaction at 180°C for 1-10h. The reaction product is ultrasonicated, cleaned, and naturally air-dried to obtain TiO 2 Nanoarrays;

[0013] The molar ratio of the titanium source to the hydrochloric acid is 1:17 to 1:70;

[0014] S2. Preparation of TiO 2 -WO 3 Composite nanomaterials

[0015] Add tungsten source to deionized water, adjust pH with prepared hydrochloric acid solution and solid acid, add rubidium sulfate as orientation growth agent, and place the TiO2 grown in step S1 on the 2 The conductive glass of the nanoarray is placed in the prepared precursor solution and subjected to hydrothermal reaction at 180°C for 1-6 hours. The reaction product is ultrasonicated, cleaned, and naturally air-dried to obtain TiO 2 -WO 3 Composite nanomaterials, including WO 3 The morphology is nanorods;

[0016] The concentration of the tungsten source is: 18mmol / L to 146mmol / L;

[0017] S3. Preparation of TiO 2 -WO 3 -Co 3 O 4 Composite nanomaterials

[0018] The loaded TiO prepared in step S2 2 -WO 3 The conductive glass of the composite nanomaterial is immersed in anhydrous ethanol, and a cobalt source and oleylamine are added, mixed and dissolved, and then hydrothermally reacted at 180-200°C for 1-10h. The reaction product is ultrasonically cleaned and naturally air-dried to obtain TiO 2 -WO 3 -Co 3 O 4 Composite nanomaterials, including Co 3 O 4 It is a nanoparticle;

[0019] The cobalt source concentration is 0.01 mol / L to 0.05 mol / L.

[0020] Furthermore, the above-mentioned TiO 2 -WO 3 -Co 3 O 4 In the method for preparing a composite nano-array catalytic material, the titanium source described in step S1 is tetrabutyl titanate.

[0021] Furthermore, the above-mentioned TiO 2 -WO 3 -Co 3 O 4 The preparation method of the composite nano-array catalytic material, the pH in step S2 is 2.

[0022] Furthermore, the above-mentioned TiO 2 -WO 3 -Co 3 O 4 In the method for preparing a composite nano-array catalytic material, the hydrochloric acid solution in step S2 is 3 mol / L.

[0023] Furthermore, the above-mentioned TiO 2 -WO 3 -Co 3 O 4 In the method for preparing a composite nano-array catalytic material, the solid acid described in step S2 is oxalic acid dihydrate.

[0024] Furthermore, the above-mentioned TiO2 -WO 3 -Co 3 O 4 In the method for preparing a composite nano-array catalytic material, the cobalt source in step S3 is cobalt nitrate.

[0025] Furthermore, the above-mentioned TiO 2 -WO 3 -Co 3 O 4 In the preparation method of the composite nano-array catalytic material, the ultrasonication and cleaning steps in the ultrasonication, cleaning and natural air drying described in step s3 require acetone as a cleaning agent.

[0026] The second technical solution provided by the present invention is the above-mentioned TiO 2 -WO 3 -Co 3 O 4 The composite nano-array catalytic material is prepared by the method provided by the first technical solution.

[0027] The last technical solution of the present invention is to provide the above-mentioned TiO 2 -WO 3 -Co 3 O 4 Composite nanoarray catalytic materials are used in photothermal catalytic cyclohexane oxidation reaction.

[0028] Compared with the prior art, the technical solution provided by the present invention has the following technical advantages:

[0029] A TiO prepared by the present invention 2 -WO 3 -Co 3 O 4 Composite nanoarray catalytic materials, by 2 WO growth on nanoarray 3 Nanorods and Co 3 O 4 nanoparticles, forming a double heterostructure, allowing its electrons to pass from the photocatalyst TiO 2 -WO 3 Transfer to the thermal catalyst Co 3 O 4 In terms of the structure, the nesting of nanoarray composite nanorods and nanoparticles can maximize the contact area between the catalyst and the reactant, improve its catalytic activity, and solve the problem of low conversion rate of photocatalytic reaction. At the same time, growing the catalyst on the glass surface can avoid the problem of subsequent separation of the catalyst and save process costs.

[0030] The technical solution provided by the present invention utilizes the good spectral absorption of the nanoarray structure and applies it to the field of photocatalytic oxidation of alkanes (cyclohexane) reactions, thereby improving the light absorption effect and thus improving the reaction catalytic efficiency; the photocatalyst and the thermal catalyst are efficiently compounded together through multi-layer nesting of different nanomorphologies (nanoarray nanorods and nanoparticles), effectively reducing the activation energy of the reaction, and utilizing the synergistic effect of light and heat to improve its conversion rate; the practicality lies in growing the catalyst on the glass surface, providing a feasible idea for the subsequent separation of the products of cyclohexane oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The TiO 2 -WO 3 -Co 3 O 4 Schematic diagram of the structure of the composite nanoarray catalytic material;

[0032] Figure 2 TiO 2 -WO 3 -Co 3 O 4 Schematic diagram of the application of composite nanoarray catalytic materials in cyclohexane oxidation reaction;

[0033] Figure 3 TiO 2 Structural characterization (XRD, FTIR, Raman) and performance testing (UV-vis and Mott-Schottky) of nanoarray catalytic materials;

[0034] Figure 4 TiO 2 Morphology of nanoarray catalytic materials (SEM);

[0035] Figure 5 For WO 3 Structural characterization (XRD) and performance testing (UV-vis and Mott-Schottky) of nanorods;

[0036] Figure 6 , 7 TiO 2 -WO 3 Morphology (SEM) and composition analysis (EDS, mapping) of nanocomposite array catalytic materials;

[0037] Figure 8 TiO 2 -WO 3 -Co 3 O 4 Composition analysis (EDS, mapping) and morphology (SEM) of nanocomposite array catalytic materials;

[0038] Fig. 9 TiO 2 , WO 3 、TiO 2 -WO 3 , WO 3 -Co 3 O 4 、TiO 2 -Co 3 O 4 、TiO 2 -WO 3 -Co 3 O 4 Performance comparison of nanocomposite array catalytic materials used in photothermal catalytic cyclohexane oxidation reaction;

[0039] Fig.10 TiO 2 -WO 3 and photothermal catalyst TiO 2 -WO 3 -Co 3 O 4 and TiO 2 -Co 3 O 4 -WO 3 Powdered catalyst TiO 2 -WO 3 -Co 3 O 4 Comparison of the performance of cyclohexane oxidation reaction under photocatalytic and thermal catalytic conditions;

[0040] Fig.11 TiO 2 Gas chromatogram of the nanoarray catalyst applied to the photothermal catalytic cyclohexane oxidation reaction;

[0041] Fig.12 For WO 3 Gas chromatogram of the photothermal catalytic cyclohexane oxidation reaction using nanorod array catalytic materials;

[0042] Fig.13 TiO 2 -WO 3 Gas chromatogram of the composite photocatalyst applied to photothermal catalytic cyclohexane oxidation reaction;

[0043] Fig.14 For WO 3 -Co 3 O 4 Gas chromatogram of the composite photothermal nanoarray catalyst applied to photothermal catalytic cyclohexane oxidation reaction;

[0044] Fig.15 TiO 2 -Co 3 O 4 Gas chromatogram of the composite photothermal nanoarray catalyst applied to photothermal catalytic cyclohexane oxidation reaction;

[0045] Fig.16 TiO 2 -WO 3 -Co 3 O 4 Gas chromatogram of the composite photothermal nanoarray catalyst applied to photothermal catalytic cyclohexane oxidation reaction;

[0046] Fig.17 TiO 2 -WO 3 -Co 3 O 4 Gas chromatogram of the composite photothermal nanoarray catalyst applied to thermal catalytic cyclohexane oxidation reaction;

[0047] Fig.18 TiO 2 -Co 3 O 4 -WO 3 Gas chromatogram of the composite powder catalyst used in thermal catalytic cyclohexane oxidation reaction; DETAILED DESCRIPTION

[0048] The claims of the present invention are further described in detail below in conjunction with specific embodiments, but do not constitute any limitation to the present invention. Any limited modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0049] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the present technical field.

[0050] The TiO 2 -WO 3 -Co 3 O 4 Schematic diagram of the structure of the composite nanoarray catalytic material Figure 1 shown.

[0051] Example 1

[0052] This embodiment provides a TiO 2 -WO 3 -Co 3 O 4 The method for preparing a composite nano-array catalytic material comprises the following steps:

[0053] 1) TiO 2Preparation of nanoarrays

[0054] Mix 20 ml of pure water and 20 ml of concentrated hydrochloric acid, then add 0.6 ml of tetrabutyl titanate dropwise and stir for 10 minutes. Soak the cleaned FTO conductive glass with the conductive surface facing down in the prepared precursor solution, heat it to 180 ° C in a reactor for 3 hours, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO loaded on the conductive glass. 2 Nanoarray.

[0055] 2) TiO 2 -WO 3 Preparation of composite catalytic materials

[0056] Dissolve 1.5g sodium tungstate dihydrate in 25ml pure water, then add an appropriate amount of 3mol / L hydrochloric acid solution drop by drop to adjust pH=2, add 100ml pure water, and then adjust pH=2 with oxalic acid dihydrate, stir for 10 minutes to obtain a precursor solution. Measure 30ml of the precursor solution and add 0.5g rubidium sulfate to mix, soak the conductive glass prepared in step 1) with the conductive surface facing down in the above precursor solution, heat it in a reactor at 180℃ for 1 hour, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO 2 -WO 3 Composite materials, including WO 3 For nanorods.

[0057] 3) TiO 2 -WO 3 -Co 3 O 4 Preparation of composite catalytic materials

[0058] The conductive glass prepared in step 2) was completely dissolved in 60 mL of anhydrous ethanol, and 0.3 g of cobalt nitrate hexahydrate was added thereto to dissolve, and then 3 mL of oleylamine was added and stirred for 5 min. The mixture was reacted at 180 ° C for 1 hour in a polytetrafluoroethylene reactor, cooled to room temperature, washed with acetone several times, and dried naturally to obtain TiO 2 -WO 3 -Co 3 O 4 Composite catalytic materials.

[0059] Sample characterization:

[0060] Step 1) Prepared TiO 2 XRD of nanoarrays ( Figure 3 (b)) confirmed that it is TiO 2 The rutile phase of the TiO 2 The characteristic peaks ( Figure 3(a)(c), UV spectrum and Mott-Schottky potential diagram show that TiO 2 The band gap width is 3.12eV ( Figure 3 (d)(e)(f)); SEM morphology confirmed that it is a tetragonal system ( Figure 4 ).

[0061] Step 2) Prepared TiO 2 -WO 3 The EDS and mapping images of the nanocomposite array catalytic material show that the W element is evenly distributed in the TiO 2 Nanoarray Figure 6 ), the morphology SEM confirmed WO 3 In the form of nanorods loaded on TiO 2 Nanoarray top ( Figure 7 ). XRD patterns confirmed that WO 3 Hexagonal crystals have been successfully prepared, see Figure 5 (a), UV spectrum and Mott-Schottky potential diagram show that WO 3 The band gap width is 3.37eV ( Figure 5 (b)(c)(d)), and confirmed that TiO 2 -WO 3 A type II heterojunction is formed.

[0062] Step 3) Prepared TiO 2 -WO 3 -Co 3 O 4 The EDS and mapping images of the nanocomposite array catalytic material show that W and Co elements are evenly distributed in the TiO 2 Nanoarray, see Figure 8 .

[0063] Example 2

[0064] This embodiment provides a TiO 2 -WO 3 -Co 3 O 4 The method for preparing a composite nano-array catalytic material comprises the following steps:

[0065] 1) TiO 2 Preparation of nanoarrays

[0066] Mix 20 ml of pure water and 20 ml of concentrated hydrochloric acid, then add 0.3 ml of tetrabutyl titanate dropwise and stir for 10 minutes. Soak the cleaned FTO conductive glass with the conductive surface facing down in the prepared precursor solution, heat it to 180 ° C in a reactor for 3 hours, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO loaded on the conductive glass. 2 Nanoarray.

[0067] 2) TiO 2 -WO 3 Preparation of composite catalytic materials

[0068] Dissolve 3g of sodium tungstate dihydrate in 25ml of pure water, then add an appropriate amount of 3mol / L hydrochloric acid solution drop by drop to adjust the pH to 2, add 100ml of pure water, and then adjust the pH to 2 with oxalic acid dihydrate, stir for 10 minutes to obtain a precursor solution. Measure 30ml of the precursor solution and add 0.5g of rubidium sulfate to mix, soak the conductive glass prepared in step 1) with the conductive surface facing down in the above precursor solution, heat it in a reactor at 180℃ for 3 hours, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO 2 -WO 3 Composite materials, including WO 3 For nanorods.

[0069] 3) TiO 2 -WO 3 -Co 3 O 4 Preparation of composite catalytic materials

[0070] The conductive glass prepared in step 2) was completely dissolved in 60 mL of anhydrous ethanol, and 0.3 g of cobalt nitrate hexahydrate was added thereto to dissolve, and then 3 mL of oleylamine was added and stirred for 5 min. The mixture was reacted at 180 ° C for 1 hour in a polytetrafluoroethylene reactor, cooled to room temperature, washed with acetone several times, and dried naturally to obtain TiO 2 -WO 3 -Co 3 O 4 Composite catalytic materials.

[0071] Example 3

[0072] This embodiment provides a TiO 2 -WO 3 -Co 3 O 4 The method for preparing a composite nano-array catalytic material comprises the following steps:

[0073] 1) TiO 2 Preparation of nanoarrays

[0074] Mix 20 ml of pure water and 20 ml of concentrated hydrochloric acid, then add 0.9 ml of tetrabutyl titanate dropwise and stir for 10 minutes. Soak the cleaned FTO conductive glass with the conductive surface facing down in the prepared precursor solution, heat it to 180 ° C in a reactor for 3 hours, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO loaded on the conductive glass. 2 Nanoarray.

[0075] 2) TiO 2 -WO 3 Preparation of composite catalytic materials

[0076] Dissolve 1.5g sodium tungstate dihydrate in 25ml pure water, then add an appropriate amount of 3mol / L hydrochloric acid solution drop by drop to adjust pH=2, add 100ml pure water, and then adjust pH=2 with oxalic acid dihydrate, stir for 10 minutes to obtain a precursor solution. Measure 30ml of the precursor solution and add 0.5g rubidium sulfate to mix, soak the conductive glass prepared in step 1) with the conductive surface facing down in the above precursor solution, heat it in a reactor at 180℃ for 1 hour, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO 2 -WO 3 Composite materials, including WO 3 For nanorods.

[0077] 3) TiO 2 -WO 3 -Co 3 O 4 Preparation of composite catalytic materials

[0078] The conductive glass prepared in step 2) was completely dissolved in 20 mL of anhydrous ethanol, and 0.3 g of cobalt nitrate hexahydrate was added thereto to dissolve, and then 3 mL of oleylamine was added and stirred for 5 min. The mixture was reacted at 180 ° C for 3 hours in a polytetrafluoroethylene reactor, cooled to room temperature, washed with acetone several times, and naturally dried to obtain TiO 2 -WO 3 -Co 3 O 4 Composite catalytic materials.

[0079] Example 4

[0080] This embodiment provides a TiO 2 -WO 3 -C o3 O 4 The method for preparing a composite nano-array catalytic material comprises the following steps:

[0081] 4) TiO 2Preparation of nanoarrays

[0082] Mix 20 ml of pure water and 20 ml of concentrated hydrochloric acid, then add 1.2 ml of tetrabutyl titanate dropwise and stir for 10 minutes. Soak the cleaned FTO conductive glass with the conductive surface facing down in the prepared precursor solution, heat it to 180 ° C in a reactor for 3 hours, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO loaded on the conductive glass. 2 Nanoarray.

[0083] 5) TiO 2 -WO 3 Preparation of composite catalytic materials

[0084] Dissolve 3g of sodium tungstate dihydrate in 25ml of pure water, then add an appropriate amount of 3mol / L hydrochloric acid solution drop by drop to adjust the pH to 2, add 100ml of pure water, and then adjust the pH to 2 with oxalic acid dihydrate, stir for 10 minutes to obtain a precursor solution. Measure 30ml of the precursor solution and add 0.5g of rubidium sulfate to mix, soak the conductive glass prepared in step 1) with the conductive surface facing down in the above precursor solution, heat it in a reactor at 180℃ for 3 hours, cool it to room temperature, ultrasonically wash it with deionized water for 10 minutes, and air dry it naturally to obtain TiO 2 -WO 3 Composite materials, including WO 3 For nanorods.

[0085] 6) TiO 2 -WO 3 -Co 3 O 4 Preparation of composite catalytic materials

[0086] The conductive glass prepared in step 2) was completely dissolved in 20 mL of anhydrous ethanol, and 0.3 g of cobalt nitrate hexahydrate was added thereto to dissolve, and then 3 mL of oleylamine was added and stirred for 5 min. The mixture was reacted at 180 ° C for 3 hours in a polytetrafluoroethylene reactor, cooled to room temperature, washed with acetone several times, and naturally dried to obtain TiO 2 -WO 3 -Co 3 O 4 Composite catalytic materials.

[0087] Application Example 1

[0088] This application example uses the TiO 2 -WO 3 -Co 3 O 4 The composite nano-array catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0089] Loading TiO 2 -WO 3 -Co 3 O 4 The conductive glass of the composite photothermal catalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0090] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110°C; reaction time is 8h; reaction light source is the ultraviolet partial area light source (300-780nm) of xenon lamp;

[0091] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The conversion rate was calculated to be 7.8% and the selectivity was 98.9%.

[0092] Application Example 2

[0093] This application example uses the TiO 2 -WO 3 -Co 3 O 4 The composite nano-array catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0094] Loading TiO 2 -WO 3 -Co 3 O 4 The conductive glass of the composite photothermal catalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0095] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110℃; reaction time is 8h; reaction light source is no light source;

[0096] After the reaction, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The conversion rate was calculated to be 3.65%, and the selectivity was 97.95%. The sample was recorded as TiO 2 -WO 3 -Co 3 O 4 -TC.

[0097] Comparative application example 1

[0098] This comparative application example uses the TiO 2 The nano-array catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0099] Loading TiO2 The conductive glass of the nanoarray catalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0100] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110°C; reaction time is 8h; reaction light source is the ultraviolet partial area light source (300-780nm) of xenon lamp;

[0101] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The calculated conversion rate was 2.37% and the selectivity was 97.04%.

[0102] Comparative Application Example 2

[0103] This application example uses the WO provided in Example 1 3 The nanorod catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0104] Load WO 3 The conductive glass of the nanorod photocatalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0105] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110℃; reaction time is 8h; reaction light source is ultraviolet partial area light source of xenon lamp (300-780nm)

[0106] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The calculated conversion rate was 3.37% and the selectivity was 97.76%.

[0107] Comparative Application Example 3

[0108] This application example uses the TiO 2 -Co 3 O 4 The composite nano-array catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0109] Loading TiO 2 -Co 3 O 4 The conductive glass of the composite photothermal catalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0110] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110℃; reaction time is 8h; reaction light source is ultraviolet partial area light source of xenon lamp (300-780nm)

[0111] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The calculated conversion rate was 6.71% and the selectivity was 98.72%.

[0112] Comparative Application Example 4

[0113] This application example uses the WO provided in Example 1 3 -Co 3 O 4 The composite nano-array catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0114] Load WO 3 -Co 3 O 4 The conductive glass of the composite photothermal catalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0115] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110℃; reaction time is 8h; reaction light source is ultraviolet partial area light source of xenon lamp (300-780nm)

[0116] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The conversion rate was calculated to be 5.1% and the selectivity was 98.55%.

[0117] Comparative Application Example 5

[0118] This application example uses the TiO 2 -WO 3 The composite nano-array catalytic material catalyzes the photothermal catalytic reaction of cyclohexane, and the reaction process specifically includes the following steps:

[0119] Loading TiO 2 -WO 3 The conductive glass of the composite photocatalytic material was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile, with the catalyst side facing upwards;

[0120] Reaction conditions: reaction pressure is 1.5 MPa dry air pressure, reaction temperature is 110° C.; reaction time is 8 h; reaction light source is the ultraviolet partial area light source (300-780 nm) of a xenon lamp.

[0121] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The calculated conversion rate was 3.74% and the selectivity was 97.93%.

[0122] Comparative Application Example 6

[0123] 0.9669 g of cobalt nitrate was dissolved in TiO 2 The carrier was immersed in pure water at 200W ultrasound for 4 hours, dried at 110℃, calcined at 500℃ for 4 hours, dissolved in pure water, and then 0.2125g of ammonium metatungstate was added. After immersion in 200W ultrasound for 4 hours, it was dried at 110℃ and calcined at 500℃ for 4 hours to obtain TiO 2 -Co 3 O 4 -WO 3 Powder type catalyst.

[0124] The same mass of TiO 2 -Co 3 O 4 -WO 3 The powdered catalyst was dissolved in a mixture of 12 mL of cyclohexane and 8 mL of acetonitrile;

[0125] Reaction conditions: reaction pressure is 1.5MPa dry air pressure, reaction temperature is 110℃; reaction time is 8h; reaction light source is ultraviolet partial area light source of xenon lamp (300-780nm)

[0126] After the reaction was completed, the product was detected by gas chromatography, and the contents of cyclohexanol and cyclohexanone were determined by the internal standard method. The calculated conversion rate was 3.84% and the selectivity was 97.98%.

[0127] Through the above application examples and comparative application examples, it can be seen that compared with TiO 2 Nanoarray, WO 3 Nanorods, TiO 2 -WO 3 Composite photocatalyst, TiO 2 -Co 3 O 4 Composite photothermal catalyst, WO 3 -Co 3 O 4 Composite photothermal catalyst, TiO in application example 1 2 -WO 3 -Co 3 O 4 The conversion rate of photothermal cyclohexane oxidation of the composite photothermal catalyst is higher than that of pure TiO 2 3.29 times of WO 3 2.3 times of that of the photothermal material TiO 2 -WO 3 -Co 3 O 4 Compared with the photocatalytic composite material TiO 2 -WO 3The conversion rate of TiO2 is 2.08 times that of TiO2, which shows that the thermal catalyst is still a more efficient catalytic material and can effectively reduce the activation energy of the reaction. 2 -WO 3 -Co 3 O 4 Compared with a single photothermal composite material, its conversion rate is TiO 2 -Co 3 O 4 1.16 times of WO 3 -Co 3 O 4 1.5 times of that of the composite photocatalytic material TiO 2 -WO 3 The type II heterojunction indeed inhibits the recombination of photogenerated holes and electrons, improving its photocatalytic conversion efficiency; at the same time, according to the conditions of photothermal and pure thermal conditions, TiO 2 -WO 3 -Co 3 O 4 The conversion rate of the composite photothermal catalytic material is 2.13 times different, which also confirms that the effect of photothermal synergy is better than any single condition. Compared with the powder catalyst and the nanoarray catalyst, under the same catalyst, the conversion rate of the nanoarray structure is 2.03 times that of the powder structure, which shows that the array structure is better than the powder structure.

Claims

1. A TiO 2 -WO 3 -Co 3 O 4 Preparation method of composite nano-array catalytic material, It is characterized in that The following steps are included in sequence: S1. Preparation of TiO 2 Nanoarray: Add titanium source to deionized water, and use hydrochloric acid to adjust the pH of the solution to acidic. Place the cleaned conductive glass obliquely into the prepared precursor solution and perform hydrothermal reaction at 180°C for 1-10h. The reaction product is ultrasonicated, cleaned, and naturally air-dried to obtain TiO 2 Nanoarrays; The molar ratio of the titanium source to the hydrochloric acid is 1:17 to 1:70; The titanium source is tetrabutyl titanate; S2. Preparation of TiO 2 -WO 3 Composite nanomaterials A tungsten source was added to deionized water, and the pH was adjusted using a prepared hydrochloric acid solution and solid acid oxalic acid dihydrate. 2 The conductive glass of the nanoarray is placed in the prepared precursor solution and subjected to hydrothermal reaction at 180°C for 1-6 hours. The reaction product is ultrasonicated, cleaned, and naturally air-dried to obtain TiO 2 -WO 3 Composite nanomaterials, including WO 3 The morphology is nanorods; The concentration of the tungsten source is: 18mmol / L ~ 146mmol / L; S3. Preparation of TiO 2 -WO 3 -Co 3 O 4 Composite nanomaterials The loaded TiO prepared in step S2 2 -WO 3 The conductive glass of the composite nanomaterial is immersed in anhydrous ethanol, and a cobalt source and oleylamine are added, mixed and dissolved, and then hydrothermally reacted at 180-200°C for 1-10h. The reaction product is ultrasonically cleaned and naturally air-dried to obtain TiO 2 -WO 3 -Co 3 O 4 Composite nanomaterials, including Co 3 O 4 It is a nanoparticle; The cobalt source concentration is 0.01mol / L to 0.05mol / L.

2. A TiO according to claim 1 2 -WO 3 -Co 3 O 4 Preparation method of composite nano-array catalytic material, It is characterized in that The pH in step S2 is 2.

3. A TiO according to claim 1 2 -WO 3 -Co 3 O 4 Preparation method of composite nano-array catalytic material, It is characterized in that The hydrochloric acid solution described in step S2 is 3 mol / L.

4. A TiO according to claim 1 2 -WO 3 -Co 3 O 4 Preparation method of composite nano-array catalytic material, It is characterized in that The cobalt source described in step S3 is cobalt nitrate.

5. The TiO according to claim 1 2 -WO 3 -Co 3 O 4 Preparation method of composite nano-array catalytic material, It is characterized in that The cleaning in step S3 uses acetone as a cleaning agent.

6. A TiO 2 -WO 3 -Co 3 O 4 Composite nanoarray catalytic materials, It is characterized in that The method is prepared by any one of claims 1 to 5.

7. The TiO according to claim 6 2 -WO 3 -Co 3 O 4 Composite nanoarray catalytic materials are used for photothermal catalytic cyclohexane oxidation reaction.

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