Long afterglow and zinc indium sulfide composite photocatalytic material with core-shell structure as well as preparation method and application of long afterglow and zinc indium sulfide composite photocatalytic material

Abstract

The invention relates to a core-shell structured long afterglow (at) zinc indium sulfide composite photocatalytic material and a preparation method and application thereof, and particularly discloses a core-shell structured PLNPs (at) ZIS composite photocatalytic material, the core is long afterglow nanoparticles (PLNPs), the shell is zinc indium sulfide nanosheets (ZIS), the chemical formula is (x) Zn2SiO4: Ga < 3 + > (at) ZnIn2S4, x is greater than or equal to 1 and less than or equal to 16, and y is greater than or equal to 15 and less than or equal to 30. The composite material is prepared by adopting a solvothermal method and comprises the following steps: firstly, synthesizing independent PLNPs, fully dispersing the PLNPs, then uniformly mixing the PLNPs with a precursor of ZIS, and carrying out solvothermal reaction in-situ growth to form the PLNPs-ZIS composite material with the core-shell structure. The composite photocatalytic material prepared by the invention has good adsorbability and oxidation-reduction ability, shows good photocatalytic hydrogen production performance, and has good application prospects in the field of energy sources.

Description

Technical Field

[0001] The present invention belongs to the technical field of new photocatalyst materials, and in particular relates to the preparation and application of a PLNPs@ZIS composite photocatalytic material with a core-shell structure. Background Art

[0002] The extensive use of fossil energy such as coal, oil, and natural gas has greatly promoted the rapid development of human society and industry. However, the consumption of fossil fuels inevitably brings about energy and environmental problems. Using solar energy to decompose water to produce hydrogen is considered to be one of the most promising ways to solve the energy and environmental crisis. By using solar energy to decompose water to produce hydrogen technology, sustainable energy production and utilization can be achieved.

[0003] Ternary Metal Sulfide ZnIn 2 S 4 Due to its non-toxicity, narrow bandgap, and easy coupling with other semiconductor catalysts, it is a photocatalytic material with good application prospects. However, its low separation efficiency of photogenerated electrons and holes limits its application. In order to further improve the 2 S 4 To better meet the needs of practical applications, existing research has further improved the catalytic performance of ZnIn by doping metal ions, controlling morphology and constructing heterojunctions. 2 S 4 catalytic performance. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation method and application of a core-shell structured PLNPs@ZIS composite photocatalytic material in view of the deficiencies in the prior art. The composite material is a (x) long afterglow nanomaterial@(y) zinc indium sulfide material composite material (1≤x≤16, 15≤y≤30). The (x) long afterglow nanomaterial@(y) zinc indium sulfide material composite material has good adsorption, redox ability and a stable core-shell heterogeneous structure.

[0005] The present invention grows zinc indium sulfide material in situ on the surface of long afterglow nanomaterial to construct a core-shell heterostructure composite photocatalytic material to help improve ZnIn 2 S 4 Photogenerated electron and hole separation efficiency is improved by ZnIn 2 S 4 The catalytic performance of this material has great scientific research significance and social and economic value.

[0006] The technical solution of the present invention:

[0007] A core-shell structured long afterglow@zinc indium sulfide (PLNPs@ZIS) composite photocatalytic material, wherein the composite photocatalytic material is: (x) long afterglow nanomaterial@(y) zinc indium sulfide material, the chemical formula of which is (x)Zn 2 SiO 4 :Ga 3+ @(y)ZnIn 2 S 4 , 1≤x≤16, 15≤y≤30, the composite catalyst with the best effect is obtained by doping in different proportions, wherein x and y are the mass fractions of the long afterglow nanomaterial and the zinc indium sulfide material respectively. The x is preferably 4, and y is preferably 15.

[0008] The present invention also provides a method for preparing the above-mentioned PLNPs@ZIS composite photocatalytic material, comprising the following preparation steps:

[0009] (1) Preparation of long afterglow nanomaterials;

[0010] Zn was added in a molar ratio of 1:0.01:0.5:2. 2+ Metal salts, Ga 3+ Metal salts, Si 4+ The compound and citric acid are added to (200 ml) water, stirred at room temperature for 1 to 3 hours to make them uniformly mixed, and then dried at 60 to 120° C. for 12 to 36 hours to obtain a dry gel; the produced dry gel is fully ground and annealed at 400 to 800° C. for 1 to 3 hours, cooled and fully ground, and further annealed at 800 to 1200° C. for 1 to 3 hours, and Zn is fully ground. 2 SiO 4 :Ga 3+ Long afterglow nanomaterials.

[0011] Furthermore, the Zn 2+ The metal salt includes zinc nitrate, zinc acetate or zinc chloride, wherein the Ga 3+ The metal salt includes gallium nitrate, the Si 4+ Compounds include silicon chloride or tetraethyl silicate.

[0012] (2) Preparation of long afterglow nanomaterial@zinc indium sulfide composites

[0013] Weigh different masses of Zn 2 SiO 4 :Ga 3+ The long afterglow nanomaterials were fully dispersed in a glycerol aqueous solution by ultrasound, and then Zn was added in a dosage ratio of 0.4mmol:0.8mmol:3.2mmold according to the stoichiometric relationship in the chemical formula. 2+ Metal salts, In 3+Metal salt, thioacetamide (ZnIn generated at this ratio 2 S 4 The mass is 150 mg), stirred vigorously for 20-60 min, then reacted at 60-100 ° C for 0.5-2.5 h, cooled to room temperature, washed with water and anhydrous ethanol, and dried at 40-80 ° C to obtain the target product (x) Zn 2 SiO 4 :Ga 3+ @(y)ZnIn 2 S 4 , 1≤x≤16, 15≤y≤30. Where x, y is the mass ratio of the two materials.

[0014] The present invention also provides the application of PLNPs@ZIS composite photocatalytic material - (x) long afterglow nanomaterial @ (y) zinc indium sulfide material, which is used for photocatalytic decomposition of water to produce hydrogen and degrade organic pollutants.

[0015] Furthermore, the sacrificial agent used in the hydrogen production is Na 2 S·9H 2 O(0.35M) and Na 2 SO 3 (0.25M) aqueous solution. The light source is a 300W xenon lamp.

[0016] Furthermore, the amount of the PLNPs@COFs composite photocatalytic material added to the sacrificial agent solution is 5-10 mg, preferably 5 mg, per 100 ml of solution. The photocatalytic reaction time is 4-6 hours.

[0017] Advantages and beneficial effects of the present invention:

[0018] The preparation method of the present invention is simple and easy, the raw materials are cheap and easy to obtain, and the equipment and process are simple and easy to operate; the method of the present invention has the advantages of small reagent pollution and good reaction repeatability. The prepared (x) long afterglow nanomaterial @ (y) zinc indium sulfide material PLNPs@ZIS (4:15) composite photocatalytic material shows good effect in the process of photocatalytic decomposition of water to produce hydrogen, and the photocatalytic performance is stable. The present invention in situ grows zinc indium sulfide on the surface of the long afterglow nanomaterial to obtain a composite material with a core-shell structure, which can achieve efficient degradation of pollutants and decomposition of water for hydrogen evolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the XRD spectrum of the PLNPs@ZIS composite photocatalytic material prepared in Example 1.

[0020] Figure 2 This is the TEM of the PLNPs@ZIS composite photocatalytic material prepared in Example 1.

[0021] Figure 3 This is a diagram showing the photocatalytic hydrogen production effect of the PLNPs@ZIS composite photocatalytic material prepared in Example 1. DETAILED DESCRIPTION

[0022] In order to make the invention purpose, technical scheme and beneficial technical effect of the present invention clearer, the present application is further described in detail in conjunction with the embodiments below. It should be understood that the embodiments described in this specification are only for explaining the present application, not for limiting the present application.

[0023] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unclearly recorded range; and any lower limit can be combined with other lower limits to form an unclearly recorded range, and any upper limit can be combined with any other upper limit to form an unclearly recorded range. In addition, although not clearly recorded, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unclearly recorded range.

[0024] The first aspect of the present application provides a long afterglow / zinc indium sulfide composite material, wherein the long afterglow / carbon dot composite nanomaterial is PLNPs@ZIS, and the chemical formula is (x)Zn 2 SiO 4 :Ga 3+ @(y)ZnIn 2 S 4 , wherein the mass fraction ratio ranges from 1≤x≤16, 15≤y≤30. In some embodiments of the present invention, (x)Zn 2 SiO 4 :Ga 3+ @(y)ZnIn 2 S 4 The mass fraction ratio in is preferably x:y=4:15.

[0025] The second aspect of the present invention provides a method for preparing a long afterglow / zinc indium sulfide composite material, the preparation method specifically comprising:

[0026] S1. Zn was added in a molar ratio of 1:0.01:0.5:2. 2+ Metal salts, Ga 3+ Metal salts, Si 4+The compound and citric acid are added to 200 ml of water, stirred at room temperature for 1 to 3 hours to make them uniformly mixed, and then dried at 60 to 120° C. for 12 to 36 hours to obtain a dry gel; the produced dry gel is fully ground and annealed at 400 to 800° C. for 1 to 3 hours, cooled and fully ground, and further annealed at 800 to 1200° C. for 1 to 3 hours, and Zn is fully ground. 2 SiO 4 :Ga 3+ Long afterglow nanomaterials.

[0027] According to the above experimental conditions, the pH value of the precursor mixture is changed, the calcination temperature and calcination time are adjusted, and finally the optimal preparation conditions of this long afterglow nanomaterial can be determined;

[0028] Furthermore, the Zn 2+ The metal salt includes zinc nitrate, zinc acetate or zinc chloride. Preferably, the Zn 2+ The metal salt is zinc nitrate;

[0029] Preferably, the Ga 3+ The metal salt is gallium nitrate;

[0030] Furthermore, the Si 4+ The compound includes silicon chloride or tetraethyl silicate, preferably, the Si 4+ The compound is tetraethyl silicate;

[0031] Preferably, the stirring time at room temperature is 2h;

[0032] Preferably, the drying temperature is 80°C and the drying time is 24h;

[0033] Preferably, the initial annealing temperature is 600°C and the annealing time is 2h;

[0034] Preferably, the second annealing temperature is 1000° C. and the annealing time is 2 hours.

[0035] S2. Weigh different masses of Zn 2 SiO 4 :Ga 3+ The long afterglow nanomaterial is fully dispersed in a propylene glycol aqueous solution by ultrasound, and then zinc chloride, indium chloride, and thioacetamide are added in a dosage ratio of 0.4mmol:0.8mmol:3.2mmold according to the stoichiometric relationship in the chemical formula, and stirred vigorously for 20-60min, and then reacted at 60-100°C for 0.5-2.5h. After cooling to room temperature, it is washed with water and anhydrous ethanol, and dried at 40-80°C to obtain the target product x long afterglow nanomaterial @ zinc indium sulfide. Among them, (x)Zn 2 SiO 4 :Ga3+ @(y)ZnIn 2 S 4 Here, the values ​​of x and y are 1≤x≤16 and 15≤y≤30 respectively.

[0036] In some specific implementations, the specific operations are as follows:

[0037] Weigh 5-80 mg of Zn 2 SiO 4 :Ga 3+ The long afterglow nanomaterial is fully dispersed in a 10% to 30% glycerol aqueous solution by ultrasound, and then 0.4 mmol zinc chloride, 0.8 mmol indium chloride, and 3.2 mmol thioacetamide (ZnIn generated at this ratio) are added. 2 S 4 The mass is 150 mg, that is, Zn 2 SiO 4 :Ga 3+ Long afterglow nanomaterials and ZnIn 2 S 4 The mass ratio of 5-80mg:150mg) was vigorously stirred for 20-60min, and then reacted at 60-100°C for 0.5-2.5h. After cooling to room temperature, the mixture was washed with water and anhydrous ethanol, and dried at 40-80°C to obtain the target product x long afterglow nanomaterial @ zinc indium sulfide.

[0038] Preferably, the optimal mass ratio of the composite material is 4:15;

[0039] Preferably, the concentration of glycerol is 20%;

[0040] Preferably, the Zn 2+ The metal salt is zinc chloride;

[0041] Preferably, the In 3+ The metal salt is indium chloride;

[0042] Preferably, the vigorous stirring time is 30 min;

[0043] Preferably, the reaction temperature is 80°C and the reaction time is 2h;

[0044] Preferably, the drying temperature is 60°C.

[0045] Example 1

[0046] S1. Zinc nitrate, gallium nitrate, tetraethoxysilane and citric acid were added to 200 ml of water in a molar ratio of 1:0.01:0.5:2, stirred at room temperature for 2 h to make them uniformly mixed, and then dried at 100 ° C for 24 h to obtain a dry gel; the resulting dry gel was fully ground and annealed at 600 ° C for 2 h, cooled and fully ground, and further annealed at 1000 ° C for 2 h, and Zn was fully ground. 2 SiO 4 :Ga 3+ Long afterglow nanomaterials.

[0047] S2. Weigh 40 mg of Zn 2 SiO 4 :Ga 3+ The long afterglow nanomaterial was fully dispersed in a glycerol aqueous solution by ultrasound, and then 0.4 mmol zinc chloride, 0.8 mmol indium chloride, and 3.2 mmol thioacetamide (ZnIn generated at this ratio) were added. 2 S 4 The mass was 150 mg), stirred vigorously for 30 min, and then reacted at 80 ° C for 2 h. After cooling to room temperature, it was washed with water and anhydrous ethanol and dried at 60 ° C to obtain PLNPs@ZIS (4:15).

[0048] Embodiment 2:

[0049] The same as Example 1, except that: the Zn weighed in step S2 2 SiO 4 :Ga 3+ The long afterglow nanomaterial was 5 mg, and the prepared composite nanomaterial was PLNPs@ZIS (1:30).

[0050] Embodiment 3:

[0051] The same as Example 1, except that: the Zn weighed in step S2 2 SiO 4 :Ga 3+ The long afterglow nanomaterial is 10 mg, and the prepared composite nanomaterial is PLNPs@ZIS (1:15).

[0052] Embodiment 4:

[0053] The same as Example 1, except that: the Zn weighed in step S2 2 SiO 4 :Ga 3+ The long afterglow nanomaterial is 20 mg, and the prepared composite nanomaterial is PLNPs@ZIS (2:15).

[0054] Embodiment 5:

[0055] The same as Example 1, except that: the Zn weighed in step S2 2 SiO 4 :Ga 3+ The long afterglow nanomaterial is 80 mg, and the prepared composite nanomaterial is PLNPs@ZIS (8:15).

[0056] Different masses of PLNPs and a fixed mass of ZIS precursor (i.e., 0.055 g zinc chloride (0.4 mmol), 0.177 g indium chloride (0.8 mmol), and 0.24 g thioacetamide (3.2 mmol)) were mixed to produce 150 mg ZnIn 2 S 4 ) and PLNPs@ZIS composites with different ratios can be prepared by in situ growth through solvothermal reaction, namely (x=1, y=30), (x=1, y=15), (x=2, y=15), (x=4, y=15) and (x=8, y=15). We prepared PLNPs@ZIS(1:30), PLNPs@ZIS(1:15), PLNPs@ZIS(2:15), PLNPs@ZIS(4:15) and PLNPs@ZIS(8:15). The photocatalytic degradation experiment showed that with the increase of the ratio of the composite material, the catalytic performance first increased and then decreased. Among them, the PLNPs@ZIS(4:15) composite material had the best photocatalytic hydrogen evolution performance.

[0057] Figure 1 This is the XRD diagram of (x) long afterglow nanomaterial @ (y) zinc indium sulfide composite photocatalytic material. Through characterization, it was observed that the diffraction peak of the composite material is consistent with the characteristic diffraction peaks of the two materials.

[0058] Figure 2 This is the TEM image of Example 1. Through transmission electron microscopy, it was observed that zinc indium sulfide was wrapped on the surface of the long afterglow nanomaterial, the long afterglow nanomaterial was the core, and the zinc indium sulfide material was the shell.

[0059] Figure 3 This is a diagram of the photocatalytic hydrogen production efficiency of (x) long afterglow nanomaterials @ (y) zinc indium sulfide composite photocatalysts, proving that the composite photocatalysts have good photocatalytic hydrogen production capabilities, among which Example 1 has the best catalytic performance.

[0060] Although the present invention is described by way of embodiments, the embodiments are not intended to limit the present invention. Those skilled in the art may make various modifications and improvements within the scope of the spirit of the present invention, such as adjustment of the ratio of ingredients or the time range, and the effect after such adjustment is predictable, so it is also within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope defined by the technical features identical or equivalent to the claims of this application.

Claims

1. A core-shell structured long afterglow@zinc indium sulfide composite photocatalytic material, characterized in that: The composite photocatalyst material is: PLNPs@ZIS, the chemical formula is (x)Zn2SiO4:Ga 3+ @(y)ZnIn2S4, 1≤x≤16, 15≤y≤30.

2. The long afterglow@zinc indium sulfide composite photocatalytic material according to claim 1, characterized in that: The chemical formula (x) is Zn2SiO4:Ga 3+ @(y)The mass fraction ratio x:y in ZnIn2S4 is 4:

15.

3. A method for preparing the core-shell structured long afterglow@zinc indium sulfide composite photocatalytic material according to claim 1, characterized in that: The preparation method comprises: (1) Zn was added in a molar ratio of 1:0.01:0.5:

2. 2+ Metal salts, Ga 3+ Metal salts, Si 4+ The compound and citric acid are added to water, stirred at room temperature for 1 to 3 hours to make them uniformly mixed, and then dried at 60 to 120° C. for 12 to 36 hours to obtain a dry gel; the produced dry gel is fully ground and annealed at 400 to 800° C. for 1 to 3 hours, cooled and fully ground, and then further annealed at 800 to 1200° C. for 1 to 3 hours, and Zn2SiO4:Ga2O3 is fully ground. 3+ Long afterglow nanomaterials; (2) Weigh different masses of Zn2SiO4:Ga 3+ The long afterglow nanomaterials were fully dispersed in a glycerol aqueous solution by ultrasound, and then Zn was added in a dosage ratio of 0.4mmol:0.8mmol:3.2mmol according to the stoichiometric relationship in the chemical formula. 2+ Metal salts, In 3+ metal salt, thioacetamide, and vigorously stirred for 20-60 minutes, followed by reaction at 60-100°C for 0.5-2.5 hours, cooled to room temperature, washed with water and anhydrous ethanol, and dried at 40-80°C to obtain the target product (x) Zn2SiO4:Ga 3+ @(y)ZnIn2S4, 1≤x≤16, 15≤y≤30, where x, y is the mass ratio of the two materials.

4. The preparation method according to claim 3, characterized in that: The added Zn2SiO4:Ga 3+ The mass range is 5-80 mg, and different ratios of (x)Zn2SiO4:Ga are prepared by in situ growth via solvothermal reaction. 3+ @(y)ZnIn2S4 composite photocatalytic material.

5. The preparation method according to claim 3, characterized in that: The Zn 2+ The metal salt includes zinc nitrate, zinc acetate or zinc chloride, wherein the Ga 3+ The metal salt includes gallium nitrate, the In 3+ The metal salt includes indium chloride, the Si 4+ Compounds include silicon chloride or tetraethyl silicate.

6. Application of the core-shell structured long afterglow@zinc indium sulfide composite photocatalytic material according to claim 1 or 2, characterized in that: Used for photocatalytic decomposition of water to produce hydrogen and degradation of organic pollutants.

7. The use according to claim 6, characterized in that: The sacrificial agents used in the hydrogen production are aqueous solutions of Na2S·9H2O (0.35M) and Na2SO3 (0.25M).

8. The use according to claim 7, characterized in that: The amount of the PLNPs@ZIS composite photocatalytic material added to the sacrificial agent solution is 5-10 mg / 100 ml.

9. The use according to claim 8, characterized in that: The light source for the photocatalytic degradation reaction is a xenon lamp light source; the photocatalytic reaction time is 4-6 hours.

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