Photocatalytic composite material based on modified zeolite and preparation method thereof
By combining modified zeolite and amorphous WO3, and employing an electrostatic self-assembly method involving heat treatment of red mud and bark and modification with PDDA, the problems of agglomeration and deactivation of photocatalysts were solved, the charge separation efficiency was improved, and low-cost, high-efficiency photocatalytic performance and high-value utilization of materials were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-20
- Publication Date
- 2026-04-10
AI Technical Summary
Existing photocatalytic technologies suffer from catalyst agglomeration and deactivation, high recombination rates of photogenerated electron-hole pairs, unstable loading of active components, high material costs, and environmental unfriendliness, making industrialization difficult.
Modified zeolite was used as the substrate, and the pore structure was improved and conductivity was introduced by heat treatment of red mud and bark. In-ZCS was loaded by electrostatic self-assembly using PDDA modification, and oxygen-vacancy-rich amorphous state was prepared by combining a complexation-reduction strategy of amorphous WO3 to form a stable photocatalytic composite material.
It improves charge separation efficiency, solves the problem of active component shedding, reduces costs, achieves green and efficient photocatalytic performance, and promotes the high-value utilization of materials.
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Figure CN121819907A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of catalytic material synthesis, and particularly relates to a photocatalytic composite material based on modified zeolite and a preparation method thereof. BACKGROUND
[0002] As a kind of advanced oxidation process driven by solar energy, photocatalytic technology shows broad application prospects in environmental governance (dye) and energy field (such as CO2 reduction). Among them, sulfide semiconductor is considered as a potential photocatalytic material due to its suitable energy band structure and excellent visible light response activity. However, the large-scale application of this technology still faces several key technical bottlenecks: (1) catalyst easy to agglomerate and deactivate, nanoscale sulfide photocatalyst is easy to agglomerate in the use process, resulting in the reduction of active sites; at the same time, the high recombination rate of photo-generated electron-hole pairs seriously restricts its quantum efficiency; although the strategy of constructing heterojunction with other semiconductors is often used to promote charge separation, the traditional crystalline WO3 has poor conductivity, and the energy level matching degree and interface contact effect with sulfide are often not ideal, and the cocatalytic effect is limited. (2) Active component loading and stability problem, in order to facilitate the recovery and reuse of catalyst, the photocatalyst is usually loaded on the porous carrier; however, the traditional physical mixing or impregnation loading method has weak combination, which leads to the easy falling off and loss of active components in the reaction process, resulting in catalyst deactivation and possible secondary pollution; in addition, the adsorption performance and pore structure of conventional zeolite carrier need to be further improved, and the surface chemical properties are difficult to form strong synergy with active components. (3) The challenge of material cost and green preparation process, high-performance photocatalytic materials usually rely on noble metals or high-purity chemical reagents, with high preparation cost; and toxic organic solvents are often used in the synthesis process, which is not friendly to the environment; how to use low-cost and easily available raw materials, especially to realize the high-value utilization of industrial waste, and develop green and efficient preparation process, is the core problem to promote the industrialization of photocatalytic technology.
[0003] Therefore, it has become a technical problem to be solved in the field to develop a new type of photocatalytic composite material which can efficiently promote charge separation, has stable loading structure, and is low in cost and friendly to the environment. SUMMARY
[0004] In order to overcome the above-mentioned prior art defects, the purpose of the present application is to provide a modified zeolite-based photocatalytic composite material and a preparation method thereof, the modified zeolite-based photocatalytic composite material taking natural zeolite as the base, being treated by red mud and tree bark, and being modified by PDDA, loading In-ZCS by electrostatic self-assembly to solve the problem of active component falling off, and amorphous WO3 being prepared by a "complexation-reduction" strategy to obtain oxygen vacancy-rich amorphous state, thereby improving the charge separation efficiency, and the modified zeolite-based photocatalytic composite material being a new photocatalytic composite material capable of efficiently promoting charge separation, having a stable loading structure, and being low in cost and environmentally friendly.
[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions to achieve the above-mentioned purpose: The present application provides a modified zeolite-based photocatalytic composite material, which comprises the following preparation raw materials in parts by weight: modified zeolite 0.15-0.2 parts, amorphous WO3 0.02-0.04 parts, In-Zn 0.3 Cd 0.7 S 0.5-0.8 parts, CTAB 0.01 part, borax 0.02 part, polyvinyl alcohol 0.03 part, and alcohol solution 30 parts.
[0006] The modified zeolite comprises the following raw materials in mass ratio: red mud:natural zeolite:tree bark:PDDA:urea = 1.5-2:0.5-0.8:0.4:0.3:0.35-0.55; The In-Zn 0.3 Cd 0.7 S comprises the following raw materials in mass ratio: cadmium acetate:zinc acetate:thiourea:thioacetamide:doping solution:polyvinylpyrrolidone = 5:2.5:4:1-1.2:0.05-0.2:4-6; The amorphous WO3 comprises the following raw materials in mass ratio: sodium tungstate: citric acid: sodium borohydride = 2:6-8:0.02-0.04.
[0007] The preparation method of the modified zeolite comprises the following steps: S11: 1.5-2 parts of red mud, 0.5-0.8 parts of natural zeolite, and 0.4 parts of tree bark are weighed and respectively pulverized, and are mixed by sieving with a 200-mesh screen to obtain a composite material; S12: the composite material obtained in step S11 is added into 30 parts of deionized water, and is stirred at a rotation speed of 500 r / min for 10 min to obtain a suspension, 0.3 parts of PDDA and 0.35-0.55 parts of urea are weighed and added into the suspension, 0.01 mol / L nitric acid is added to adjust the pH range to 8-9, and the suspension is stirred at a rotation speed of 500 r / min for 30 min, and then is dried at a temperature of 65°C for 8 h to obtain a calcined precursor; S13: calcining the calcined precursor obtained in step S12 at a temperature of 350 DEG C for 1.5 h, and then heating the temperature to 600 DEG C for secondary calcination for 1.5 h, the heating rate being 5 DEG C / min, and then naturally cooling to room temperature, washing with deionized water for 3 times, and then drying at a temperature of 65 DEG C for 24 h to obtain the modified zeolite.
[0008] The In-Zn 0.3 Cd 0.7 The preparation method of the S (In-ZCS) is as follows: S21: 5 parts of cadmium acetate and 2.5 parts of zinc acetate are weighed and added into 70 parts of a composite alcohol solution, wherein the composite alcohol solution comprises the following materials in a mass ratio: ethylene glycol: ethanol = 7:3, and stirring is carried out at a rotating speed of 500 r / min for 2 h to obtain a clear solution; S22: 0.05-0.2 parts of a doping solution is weighed and added into the clear solution obtained in step S21, wherein the doping solution is an indium nitrate solution with a concentration of 0.2 mol / L, and stirring is carried out at a rotating speed of 500 r / min for 10 min, 4 parts of thiourea, 1-1.2 parts of thioacetamide and 4-6 parts of polyvinylpyrrolidone are weighed and added, and stirring is continued at the above rotating speed for 30 min, and then heating is carried out at a hydrothermal temperature of 140 DEG C for 15 h, and deionized water and anhydrous ethanol are alternately washed for 5 times each, and then drying is carried out at a temperature of 65 DEG C for 24 h to obtain the In-ZCS.
[0009] The preparation method of the amorphous WO3 is as follows: S31: 2 parts of sodium tungstate and 6-8 parts of citric acid are weighed and added into 50 parts of deionized water, hydrochloric acid with a concentration of 1 mol / L is added to adjust the pH range to 4-5, and stirring is carried out at a rotating speed of 500 r / min for 2 h, and then drying is carried out at a temperature of 65 DEG C for 12 h to obtain a calcined precursor; S32: 0.02-0.04 parts of sodium borohydride is weighed and added into the calcined precursor obtained in step S31, and grinding is carried out for 5 min, and then calcining is carried out at a temperature of 270 DEG C for 1.5 h, and deionized water and anhydrous ethanol are alternately washed for 3 times each, and then drying is carried out at a temperature of 65 DEG C for 24 h to obtain the amorphous WO3.
[0010] The application further provides a preparation method of the photocatalytic composite material based on the modified zeolite, and the steps are as follows: Step one, 0.01 parts of CATB is weighed and added into 30 parts of alcohol liquid, wherein the alcohol liquid comprises the following mass percentage of materials: anhydrous ethanol: deionized water = 70:30, stirring is carried out at a rotation speed of 500 r / min for 30 min to obtain an activation liquid, 0.02 parts of borax and 0.03 parts of polyvinyl alcohol are weighed and added into the obtained activation liquid, and stirring is carried out at a rotation speed of 500 r / min for 15 min to obtain a basic dispersion liquid; Step two, 0.15-0.2 parts of modified zeolite and 0.02-0.04 parts of amorphous WO3 are weighed and added into the basic dispersion liquid obtained in step one, and stirring is carried out at a rotation speed of 500 r / min for 30 min to obtain a base liquid; Step three, 0.5-0.8 parts of In-ZCS is weighed and added into the base liquid obtained in step two, stirring is carried out at a rotation speed of 500 r / min for 30 min, and heating is carried out at a temperature of 60 DEG C, then quick freezing treatment is carried out at a temperature of-50 DEG C for 12 h, deionized water and anhydrous ethanol are used to wash alternately for 3 times each time, and then drying is carried out at a temperature of 65 DEG C for 24 h to obtain a photocatalytic composite material based on modified zeolite.
[0011] Compared with the prior art, the application has the following beneficial effects: The photocatalytic composite material based on modified zeolite prepared by the application uses natural zeolite as a basic material, and is subjected to composite heat treatment with red mud and bark, so that the pore structure and surface properties of the zeolite are improved, water is used as a solvent in the whole modification process to avoid organic solvent pollution, and the addition of the bark introduces carbon components in the calcination process to improve the electrical conductivity of the zeolite, which is beneficial to the photocatalytic reaction; after modification, the zeolite has more pores, which provides more active sites for the adsorption of reactants in the catalytic process; and the surface positive charge of the modified zeolite is enhanced by PDDA treatment, and the adsorption of In-ZCS on the surface of the modified zeolite is promoted by electrostatic self-assembly, so that the problems of easy falling off and uneven distribution of active components in the traditional mixing method are effectively solved.
[0012] The photocatalytic composite material based on modified zeolite prepared by the application adopts a complexation-reduction synergistic regulation amorphous method in the amorphous process of WO3, citric acid is used as an organic complexing agent, the carboxyl group of the citric acid molecule forms a stable complex precursor with tungstate ions, the carbonization and decomposition of the citric acid molecule in the calcination process at 270 DEG C can destroy the order and long-range arrangement of the tungsten-oxygen octahedron, thereby effectively promoting the formation of amorphous WO3; and sodium borohydride is introduced to promote the reduction of part of W 6+The reduction of In-ZCS introduces a large number of oxygen vacancies to maintain the charge balance of the system, and the existence of oxygen vacancies and low-valence tungsten ions not only further disturbs the periodicity of the lattice and stabilizes the amorphous structure, but more importantly, they can significantly improve the intrinsic electron conductivity of the material and promote the separation efficiency of the photo-generated electron-hole pairs as effective electron trapping centers.
[0013] The modified zeolite-based photocatalytic composite material prepared by the application can convert low-cost and green raw materials into high-performance photocatalytic composite materials through an innovative process, realizes high-value utilization of waste, and provides a new strategy for solving the industrialization bottleneck of high-cost photocatalytic technology. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 XRD test graph of In-ZCS of Example 2; Figure 2 XRD test graph of amorphous WO3 of Example 2; Figure 3 SEM test graph of modified zeolite and In-ZCS of Example 2; (Zeta) test graph of Example 2; Figure 4 SEM graph of the photocatalytic composite material prepared in Example 2; Figure 5 CO yield and RhB test of the photocatalytic composite material prepared in the examples and comparative examples. DETAILED DESCRIPTION
[0015] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the application.
[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art. In addition, any method and material similar or equivalent to those described herein can be used in the application. The preferred implementation methods and materials described herein are only used for demonstration, but cannot limit the content of the application.
[0017] The application will be further described below with reference to specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the claims attached to the application.
[0018] The following examples use apparatus and equipment that are conventional in the art. The experimental methods in the following examples, unless otherwise specified, are generally in accordance with conventional methods, or as recommended by the manufacturer. The following examples use various raw materials, unless otherwise specified, all of which are conventional commercially available products, in conventional grades. In the specification of the present application and in the following examples, unless otherwise specified, "%" means "percent by weight", "parts" means "parts by weight", and the ratio means "ratio by weight".
[0019] The preparation method and characterization in the following examples are referred to Figures 1-5 Unless otherwise specified, all are conventional methods; the materials used in the following examples, unless otherwise specified, are all raw materials purchased on the market, and the composite alcohol solution includes the following mass ratio materials: ethylene glycol: ethanol = 7:3, the alcohol solution includes the following mass percentage of materials: anhydrous ethanol: deionized water = 70:30, and the doping solution is 0.2 mol / L indium nitrate solution.
[0020] Example 1 The present embodiment provides a modified zeolite-based photocatalytic composite material, which comprises the following raw materials by weight: modified zeolite 0.15 parts, amorphous WO3 0.02 parts, In-ZCS 0.5 parts, CTAB 0.01 parts, borax 0.02 parts, polyvinyl alcohol 0.03 parts, and alcohol solution 30 parts.
[0021] The preparation method of the modified zeolite is as follows: S11: 1.5 parts of red mud, 0.5 parts of natural zeolite and 0.4 parts of bark are weighed and respectively pulverized, mixed and sieved using a 200 mesh screen to obtain a composite material; S12: The composite material obtained in step S11 is added to 30 parts of deionized water, stirred at a speed of 500 r / min for 10 min to obtain a suspension, 0.3 parts of PDDA and 0.35 parts of urea are added, the pH is adjusted to 8 by adding 0.01 mol / L nitric acid, and stirred at a speed of 500 r / min for 30 min, and then dried at a temperature of 65°C for 8h to obtain a calcined precursor; S13: The calcined precursor obtained in step S12 is calcined at a temperature of 350°C for 1.5h, and on the basis of this temperature, the temperature is heated to 600°C for secondary calcination for 1.5h, and the heating rate is 5°C / min, and then naturally cooled to room temperature, washed with deionized water for 3 times, and then dried at a temperature of 65°C for 24h to obtain the modified zeolite.
[0022] The preparation method of In-ZCS is as follows: S21: 5 parts of cadmium acetate and 2.5 parts of zinc acetate were weighed and added into 70 parts of a composite alcohol solution, and stirring was carried out at a rotation speed of 500 r / min for 2 h to obtain a clear solution; S22: 0.05 parts of a doping solution were weighed and added into the clear solution obtained in step S21, and stirring was carried out at a rotation speed of 500 r / min for 10 min, 4 parts of thiourea, 1 part of thioacetamide and 4 parts of polyvinylpyrrolidone were weighed and added, and stirring was continued at the above rotation speed for 30 min, and then heating was carried out at a hydrothermal temperature of 140℃ for 15 h, and deionized water and anhydrous ethanol were used for alternate washing for 5 times each, and drying was carried out at a temperature of 65℃ for 24 h to obtain In-ZCS.
[0023] The preparation method of the amorphous WO3 is as follows: S31: 2 parts of sodium tungstate and 6 parts of citric acid were weighed and added into 50 parts of deionized water, hydrochloric acid with a concentration of 1 mol / L was added to adjust the pH to 4, and stirring was carried out at a rotation speed of 500 r / min for 2 h, and then drying was carried out at a temperature of 65℃ for 12 h to obtain a calcined precursor; S32: 0.02 parts of sodium borohydride were weighed and added into the calcined precursor obtained in step S31, and grinding was carried out using a mortar for 5 min, and then calcination was carried out at a temperature of 270℃ for 1.5 h, and deionized water and anhydrous ethanol were used for alternate washing for 3 times each, and drying was carried out at a temperature of 65℃ for 24 h to obtain amorphous WO3.
[0024] The preparation method of the amorphous WO3 is as follows: Step one, 0.01 parts of CATB were weighed and added into 30 parts of an alcohol solution, and stirring was carried out at a rotation speed of 500 r / min for 30 min to obtain an activation solution, 0.02 parts of borax and 0.03 parts of polyvinyl alcohol were weighed and added into the obtained activation solution, and stirring was carried out at a rotation speed of 500 r / min for 15 min to obtain a basic dispersion solution; Step two, 0.15 parts of a modified zeolite and 0.02 parts of amorphous WO3 were weighed and added into the basic dispersion solution obtained in step one, and stirring was carried out at a rotation speed of 500 r / min for 30 min to obtain a base solution; Step three, 0.5 parts of In-ZCS were weighed and added into the base solution obtained in step two, and stirring was carried out at a rotation speed of 500 r / min for 30 min, and heating was carried out at a temperature of 60℃, and then quick freezing treatment was carried out at a temperature of -50℃ for 12 h, and deionized water and anhydrous ethanol were used for alternate washing for 3 times each, and then drying was carried out at a temperature of 65℃ for 24 h to obtain a photocatalytic composite material based on a modified zeolite.
[0025] Example 2: The embodiment provides a modified zeolite-based photocatalytic composite material, which comprises the following preparation raw materials in parts by weight: 0.18 parts of modified zeolite, 0.03 parts of amorphous WO3, 0.65 parts of In-ZCS, 0.01 parts of CTAB, 0.02 parts of borax, 0.03 parts of polyvinyl alcohol and 30 parts of alcohol solution.
[0026] A preparation method of the modified zeolite, steps are as follows: S11: 1.8 parts of red mud, 0.65 parts of natural zeolite and 0.4 parts of bark are weighed and respectively pulverized, are mixed by screening with a 200-mesh screen, and a composite material is obtained; S12: the composite material obtained in step S11 is added into 30 parts of deionized water, stirring is carried out at a rotating speed of 500 r / min for 10 min, a suspension is obtained, 0.3 parts of PDDA and 0.45 parts of urea are weighed and added, 0.01 mol / L nitric acid is added to adjust the pH to 8.5, stirring is carried out at a rotating speed of 500 r / min for 30 min, and then drying is carried out at a temperature of 65 DEG C for 8 h, and a calcined precursor is obtained; S13: the calcined precursor obtained in step S12 is calcined at a temperature of 350 DEG C for 1.5 h, on the basis of the temperature, the temperature is heated to 600 DEG C for secondary calcination for 1.5 h, the heating rate is 5 DEG C / min, then natural cooling is carried out to room temperature, washing is carried out with deionized water for 3 times, and then drying is carried out at a temperature of 65 DEG C for 24 h, and a modified zeolite is obtained.
[0027] A preparation method of the In-ZCS, steps are as follows: S21: 5 parts of cadmium acetate and 2.5 parts of zinc acetate are weighed and added into 70 parts of a composite alcohol solution, stirring is carried out at a rotating speed of 500 r / min for 2 h, and a clear solution is obtained; S22: 0.13 parts of a doping solution is weighed and added into the clear solution obtained in step S21, stirring is carried out at a rotating speed of 500 r / min for 10 min, 4 parts of thiourea, 1.1 parts of thioacetamide and 5 parts of polyvinylpyrrolidone are weighed and added, stirring is continuously carried out at the rotating speed for 30 min, then heating is carried out at a hydrothermal temperature of 140 DEG C for 15 h, washing is carried out with deionized water and anhydrous ethanol alternately for 5 times each, and drying is carried out at a temperature of 65 DEG C for 24 h, and In-ZCS is obtained.
[0028] A preparation method of the amorphous WO3, steps are as follows: S31: 2 parts of sodium tungstate and 7 parts of citric acid are weighed and added into 50 parts of deionized water, 1 mol / L hydrochloric acid is added to adjust the pH to 4.5, stirring is carried out at a rotating speed of 500 r / min for 2 h, and then drying is carried out at a temperature of 65 DEG C for 12 h, and a calcined precursor is obtained; S32: 0.03 parts of sodium borohydride is weighed into the calcined precursor obtained in step S31, and is ground for 5 min using a mortar, and is then calcined under conditions of a temperature of 270 DEG C for 1.5 h, and is washed with deionized water and anhydrous ethanol alternately for 3 times each, and is dried under conditions of a temperature of 65 DEG C for 24 h, to obtain amorphous WO3.
[0029] The embodiment also provides a preparation method of the modified zeolite-based photocatalytic composite material, and steps are as follows: Step one, 0.01 parts of CTAB is weighed into 30 parts of alcohol liquid, and is stirred at a rotating speed of 500 r / min for 30 min to obtain an activation liquid, and 0.02 parts of borax and 0.03 parts of polyvinyl alcohol are weighed into the obtained activation liquid, and are stirred at a rotating speed of 500 r / min for 15 min to obtain a basic dispersion liquid; Step two, 0.18 parts of modified zeolite and 0.03 parts of amorphous WO3 are weighed into the basic dispersion liquid obtained in step one, and are stirred at a rotating speed of 500 r / min for 30 min to obtain a base liquid; Step three, 0.65 parts of In-ZCS is weighed into the base liquid obtained in step two, and is stirred at a rotating speed of 500 r / min for 30 min, and is heated under conditions of a temperature of 60 DEG C, and is then rapidly frozen under conditions of a temperature of-50 DEG C for 12 h, and is washed with deionized water and anhydrous ethanol alternately for 3 times each, and is dried under conditions of a temperature of 65 DEG C for 24 h to obtain the modified zeolite-based photocatalytic composite material.
[0030] Embodiment 3: The embodiment provides a modified zeolite-based photocatalytic composite material, and the following raw materials are used in preparation: 0.2 parts of modified zeolite, 0.04 parts of amorphous WO3, 0.8 parts of In-ZCS, 0.01 parts of CTAB, 0.02 parts of borax, 0.03 parts of polyvinyl alcohol and 30 parts of alcohol liquid.
[0031] A preparation method of the modified zeolite is as follows: S11: 2 parts of red mud, 0.8 parts of natural zeolite and 0.4 parts of bark are respectively crushed, are mixed by sieving using a 200-mesh screen to obtain a composite material; S12: the composite material obtained in step S11 is added into 30 parts of deionized water, and is stirred at a rotating speed of 500 r / min for 10 min to obtain a suspension, and 0.3 parts of PDDA and 0.55 parts of urea are weighed into the suspension, and the pH is adjusted to 9 by adding 0.01 mol / L nitric acid, and is stirred at a rotating speed of 500 r / min for 30 min, and is then dried under conditions of a temperature of 65 DEG C for 8 h to obtain a calcined precursor; S13: The calcined precursor obtained in step S12 is calcined at a temperature of 350℃ for 1.5h, and on the basis of the temperature, the temperature is heated to 600℃ for secondary calcination for 1.5h, the heating rate of the above is 5℃ / min, and then it is naturally cooled to room temperature, washed with deionized water for 3 times, and then dried at a temperature of 65℃ for 24h to obtain the modified zeolite.
[0032] The preparation method of In-ZCS is as follows: S21: 5 parts of cadmium acetate and 2.5 parts of zinc acetate are weighed and added into 70 parts of composite alcohol solution, and stirred at a rotation speed of 500r / min for 2h to obtain a clear solution; S22: 0.2 parts of doping solution are weighed and added into the clear solution obtained in step S21, and stirred at a rotation speed of 500r / min for 10min, 4 parts of thiourea, 1.2 parts of thioacetamide and 6 parts of polyvinylpyrrolidone are weighed and added, and the stirring is continued at the above rotation speed for 30min, and then heated at a hydrothermal temperature of 140℃ for 15h, washed with deionized water and anhydrous ethanol alternately for 5 times each, and dried at a temperature of 65℃ for 24h to obtain In-ZCS.
[0033] The preparation method of amorphous WO3 is as follows: S31: 2 parts of sodium tungstate and 8 parts of citric acid are weighed and added into 50 parts of deionized water, hydrochloric acid with a concentration of 1mol / L is added to adjust the pH to 5, and stirred at a rotation speed of 500r / min for 2h, and then dried at a temperature of 65℃ for 12h to obtain a calcined precursor; S32: 0.04 parts of sodium borohydride are weighed and added into the calcined precursor obtained in step S31, and ground for 5min, and then calcined at a temperature of 270℃ for 1.5h, washed with deionized water and anhydrous ethanol alternately for 3 times each, and dried at a temperature of 65℃ for 24h to obtain amorphous WO3.
[0034] The preparation method of the photocatalytic composite material based on the modified zeolite is also provided in the embodiment, and the steps are as follows: Step one, 0.01 parts of CATB are weighed and added into 30 parts of alcohol solution, and stirred at a rotation speed of 500r / min for 30min to obtain an activation solution, 0.02 parts of borax and 0.03 parts of polyvinyl alcohol are weighed and added into the obtained activation solution, and stirred at a rotation speed of 500r / min for 15min to obtain a basic dispersion solution; Step two, 0.2 parts of modified zeolite and 0.04 parts of amorphous WO3 are weighed and added into the basic dispersion solution obtained in step one, and stirred at a rotation speed of 500r / min for 30min to obtain a base solution; Step three, 0.8 parts of In-ZCS was added into the substrate solution obtained in step two, stirring was carried out at a rotation speed of 500 r / min for 30 min, and heating was carried out at a temperature of 60℃, followed by quick freezing treatment at a temperature of -50℃ for 12 h, and then deionized water and anhydrous ethanol were used for alternating washing for 3 times, and then drying was carried out at a temperature of 65℃ for 24 h, to obtain a photocatalytic composite material based on modified zeolite.
[0035] Comparative Example 1: Comparative Example 1 is different from Example 2 in that no amorphous WO3 is added, and the rest is the same as Example 2.
[0036] Comparative Example 2: Comparative Example 2 is different from Example 2 in that no In-ZCS is added, and the rest is the same as Example 2.
[0037] Comparative Example 3: Comparative Example 3 is different from Example 2 in that no modified zeolite is added, and the rest is the same as Example 2.
[0038] The following tests were carried out on the prepared photocatalytic composite material, wherein Figure 1 The XRD test chart of In-ZCS prepared in Example 2 shows that In doping does not affect the main diffraction peak of ZCS and no impurity peak appears, indicating that the prepared purity is high. Figure 2 The XRD test chart of amorphous WO3 prepared in Example 2 shows that the diffraction peak at 2θ of 28.1° corresponds to the 200 crystal face, and the diffraction peak of the 200 crystal face in the obtained XRD spectrum is flat, indicating that amorphous WO3 is successfully prepared. Figure 3 The Zeta potential test results of the modified zeolite and In-ZCS prepared in Example 2 show that the Zeta potential of In-ZCS is -15.38 mV, and the Zeta potential of the modified zeolite is 24.82 mV, indicating that the two are combined in the form of electrostatic self-assembly. Figure 4 The SEM test chart of the photocatalytic composite material prepared in Example 2 shows that the size of the modified zeolite is small and the dispersion is uniform, the amorphous WO3 is blocky structure, and the In-ZCS is nano-sheet structure, and it can be seen that the three are uniformly dispersed. Figure 5 The photocatalytic composite materials prepared in the examples and comparative examples were used for photocatalytic reduction of CO2 (30 mg of catalyst) and adsorption of RhB (5 mg / L) (100 mL, 50 mg of catalyst), wherein the CO yield of Example 2 was 17.9 μmol·g -1 ·h -1 , and the degradation rate of RhB was 96.9% in 30 min, and the overall effect was better than that of the comparative examples.
[0039] In summary, the application provides a modified zeolite-based photocatalytic composite material. Firstly, based on natural zeolite, the application innovatively uses red mud and tree bark for composite heat treatment. In a green and non-polluting aqueous phase process, the improvement of zeolite pore structure, the introduction of conductive carbon components and the surface positive charge by PDDA modification are simultaneously achieved, thereby firmly loading In-ZCS through electrostatic self-assembly, and solving the problem of easy shedding of active components. Secondly, in the preparation of WO3, a complex-reduction synergistic strategy is adopted, and amorphous WO3 rich in oxygen vacancies is directionally synthesized by using citric acid and sodium borohydride, which greatly improves the photo-induced charge separation efficiency. Finally, the design converts cheap waste into high-performance composite materials, successfully constructs an adsorption-catalysis synergistic system, and provides a new strategy for solving the industrialization cost bottleneck of photocatalytic technology.
[0040] Obviously, the above comparative examples and examples are only part of the comparative examples and examples of the application, and are within the scope of the application.
[0041] Although embodiments of the application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the application, and the scope of the application is defined by the appended claims and their equivalents.
[0042] The above describes the application and its embodiments, which is not restrictive, and the drawings only show one of the embodiments of the application, and the actual application is not limited thereto. In summary, if a person skilled in the art is inspired by it, without departing from the purpose of the application, without creativity.
Claims
1. A photocatalytic composite material based on modified zeolite, characterized in that, The preparation raw materials include the following parts by weight: 0.15-0.2 parts modified zeolite, 0.02-0.04 parts amorphous WO3, and In-Zn. 0.3 Cd 0.7 S 0.5-0.8 parts, CTAB 0.01 parts, borax 0.02 parts, polyvinyl alcohol 0.03 parts and alcohol solution 30 parts; The modified zeolite comprises raw materials in the following mass ratio: red mud: natural zeolite: bark: PDDA: urea = (1.5-2): (0.5-0.8): 0.4: 0.3: (0.35-0.55); The In-Zn 0.3 Cd 0.7 S comprises raw materials in the following mass ratio: cadmium acetate: zinc acetate: thiourea: thioacetamide: dopant: polyvinylpyrrolidone = 5: 2.5: 4: (1-1.2): (0.05-0.2): (4-6); The amorphous WO3 comprises raw materials in the following mass ratio: sodium tungstate: citric acid: sodium borohydride = 2: (6-8): (0.02-0.04).
2. The photocatalytic composite material based on modified zeolite according to claim 1, characterized in that, The preparation method of the modified zeolite is as follows: S11: A composite material is prepared by mixing red mud, natural zeolite and bark after pretreatment; S12: Add the composite material to water, stir to obtain a suspension, add PDDA and urea, adjust the pH with acid, stir, dry to obtain the calcination precursor; S13: The calcined precursor is calcined, then calcined again, washed, and dried to obtain modified zeolite.
3. The photocatalytic composite material based on modified zeolite according to claim 2, characterized in that, In S11, the pretreatment consists of sequential crushing and sieving, with the sieving using a 200-mesh screen; In S12, the mass ratio of water, red mud, natural zeolite, and bark in the suspension is 30:(1.5-2):(0.5-0.8):0.4; The acid is nitric acid, the concentration of which is 0.01 mol / L, and the pH range is 8–9. In S13, the calcination temperature is 350℃ and the calcination time is 1.5h, and the secondary calcination temperature is 600℃ and the secondary calcination time is 1.5h.
4. The photocatalytic composite material based on modified zeolite according to claim 1, characterized in that, The In-Zn 0.3 Cd 0.7 The preparation method of S is as follows: S21: Add cadmium acetate and zinc acetate to the composite alcohol solution, stir, and obtain a clear solution; S22: Add the dopant solution to the clarified solution, stir, add thiourea, thioacetamide and polyvinylpyrrolidone, stir, perform hydrothermal treatment, wash, and dry to obtain In-Zn. 0.3 Cd 0.7 S.
5. The photocatalytic composite material based on modified zeolite according to claim 4, characterized in that, In S21, the composite alcohol solution is composed of ethylene glycol and ethanol in a mass ratio of 7:3, and the mass ratio of cadmium acetate, zinc acetate and composite alcohol solution in the clarified liquid is 70:5:2.
5. In S22, the doping solution is an indium nitrate solution with a concentration of 0.2 mol / L; the hydrothermal treatment temperature is 140°C, and the hydrothermal treatment time is 15 h.
6. The photocatalytic composite material based on modified zeolite according to claim 1, characterized in that, The preparation method of the amorphous WO3 is as follows: S31: Sodium tungstate and citric acid are added to water, pH is adjusted with acid, stirred, and dried to obtain the calcination precursor; S32: Sodium borohydride is added to the calcination precursor, ground, calcined, washed, and dried to obtain amorphous WO3.
7. The photocatalytic composite material based on modified zeolite according to claim 6, characterized in that, In S31, the mass ratio of water, sodium tungstate, and citric acid is 50:2:(6-8); the acid is hydrochloric acid with a concentration of 1 mol / L; and the pH range is 4-5. In S32, the calcination temperature is 270°C and the calcination time is 1.5 hours.
8. The photocatalytic composite material based on modified zeolite according to claim 1, characterized in that, The alcohol solution comprises the following materials in the following mass percentages: anhydrous ethanol: deionized water = 70%: 30%.
9. A method for preparing a photocatalytic composite material based on modified zeolite as described in any one of claims 1-8, characterized in that, Includes the following steps: Add CATB to the alcohol solution and stir to obtain an activated solution. Then add borax and polyvinyl alcohol to the activated solution and stir to obtain a basic dispersion. Modified zeolite and amorphous WO3 were added to the basic dispersion and stirred to obtain the base solution; In-Zn 0.3 Cd 0.7 S was added to the base liquid, stirred, heated, quick-frozen, washed, and dried to obtain a photocatalytic composite material based on modified zeolite.
10. The method for preparing the photocatalytic composite material based on modified zeolite according to claim 9, characterized in that, The heating temperature is 60°C, the quick-freezing temperature is -50°C, and the time is 12 hours.