A preparation method of a catalyst for photocatalytic water splitting and synergistic degradation of pollutants based on NiS / CdS derived from Cd-PBA

Abstract

The present invention discloses a preparation method of a NiS / CdS photocatalyst for photocatalytic water splitting and synergistic degradation of pollutants derived from Cd-PBA. This preparation method uses a simple two-step sulfidation method to derivatize and prepare a NiS / CdS catalyst with a cubic core-shell structure from Cd-PBA as a precursor. First, the Cd-based Prussian blue analogue cube, i.e., the Cd-PBA cube, is transformed into a cubic core-shell structure CdS, and then further transformed into a cubic core-shell structure NiS / CdS by adding a Ni source. The Ni / CdS nanocomposite prepared by the present invention can effectively produce hydrogen by water splitting under visible light excitation and synergistically degrade pollutants. Moreover, it has a regular hollow core-shell structure, is simple to prepare, has a low cost, and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of pollutant treatment and hydrogen production through synergy, and particularly relates to a preparation method of a catalyst for photocatalytic water splitting and pollutant degradation through synergy based on NiS / CdS derived from Cd-PBA. Background Art

[0002] Environmental pollution and energy shortage are two major problems currently faced by mankind, and are of great significance for the sustainable development of human civilization. Actively developing new methods for simultaneously treating environmental pollutants and producing new energy through synergy is one of the important strategies to effectively address the above two problems.

[0003] Hydrogen energy is a clean and pollution-free fuel with a high calorific value of combustion and only produces water, and is considered an ideal clean and renewable energy source. Therefore, it has received increasing attention from more and more scholars in recent years. Photocatalytic water splitting for hydrogen production can convert nearly unlimited solar energy into valuable hydrogen energy without producing secondary pollution, and is one of the important methods for producing clean new energy. In the process of photocatalytic water splitting for hydrogen production, organic compounds need to be used as sacrificial agents to be oxidized to consume photo-generated holes to achieve better electron-hole separation, thereby improving the efficiency of photocatalytic hydrogen production. If organic pollutants are used as such sacrificial agents, it is possible to achieve the simultaneous degradation of pollutants during the process of photocatalytic water splitting for hydrogen production, thereby achieving the effect of synergistic enhancement of pollutant treatment and new energy production.

[0004] Based on the above technical background, in order to develop a method for photocatalytic water splitting for hydrogen production and pollutant degradation through synergy, the present invention prepared a NiS / CdS catalyst with a cubic core-shell structure by a simple two-step sulfidation method using Co-PBA as a precursor, in order to obtain high-efficiency visible-light photocatalytic water splitting for hydrogen evolution and pollutant degradation performance, and related technologies have not been reported. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems existing in the prior art, and provide a preparation method of a catalyst for photocatalytic water splitting and pollutant degradation through synergy based on NiS / CdS derived from Cd-PBA.

[0006] To achieve the above purpose, the technical solution provided by the present invention is: a preparation method of a catalyst for photocatalytic water splitting and pollutant degradation through synergy based on NiS / CdS derived from Cd-PBA. This preparation method prepared a NiS / CdS catalyst with a cubic core-shell structure by a simple two-step sulfidation method using Cd-PBA as a precursor; first, the Cd-based Prussian blue analogue cube, that is, the Cd-PBA cube, was transformed into a cubic core-shell structure CdS, and then further transformed into a cubic core-shell structure NiS / CdS by adding a Ni source. The specific steps are as follows:

[0007] (1) Synthesis of Cd-PBA cubes: 0.6 mmol of cadmium chloride, 1 g of PVP, and 0.35 mmol of sodium citrate were dissolved in 20 mL of water to form solution A. 0.4 mmol of K 3 [Co(CN) 6 was dissolved in 20 mL of water to form solution B. Solution B was added to solution A, and then the mixed solution was allowed to stand and age for 1 h. The product was collected by centrifugation, washed 3 times with ethanol, and then ultrasonically dispersed in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution;

[0008] (2) Synthesis of cubic core-shell structured CdS: 0.2 g of thioacetamide was dissolved in a water-alcohol mixed solvent and then added to the Cd-PBA cube solution to obtain a mixed solution C. Then, a certain amount of NH 3 ·H 2 O was added to the mixed solution C. After reacting for 30 min, the product was collected by centrifugation and washed 3 times with ethanol to obtain cubic core-shell structured CdS;

[0009] (3) Synthesis of cubic core-shell structured NiS / CdS: 0.6 g of thioacetamide and 600 μL of NH 3 ·H 2 O were added to the cubic core-shell structured CdS. After reacting for 1 h, a certain amount of 200 mM NiCl 2 and 1 mL of 100 M Na 2 S were added. After reacting for 1 h, the product was collected by centrifugation, washed 3 times with ethanol, and then dried in an oven at 70 °C to obtain a cubic core-shell structured NiS / CdS catalyst.

[0010] Preferably, the amount of NH 3 ·H 2 O added in step (2) ranges from 100 to 300 μL.

[0011] Preferably, the amount of 200 mM NiCl 2 added in step (3) ranges from 100 to 200 μL.

[0012] Advantages of the present invention:

[0013] 1. The NiS / CdS nanocomposite prepared by the present invention can effectively decompose water to produce hydrogen under visible light excitation and synergistically degrade pollutants, thereby achieving the effect of synergistic enhancement of new energy production for pollutant treatment.

[0014] 2. The NiS / CdS nanocomposite prepared by the present invention has a regular hollow core-shell structure, is simple to prepare, has a low cost, and is suitable for large-scale popularization and application. Brief Description of the Drawings

[0015] The accompanying drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0016] Figure 1 It is the transmission electron microscope image of the NiS / CdS nanocomposite prepared in Specific Example 2 of the present invention;

[0017] Figure 2 It is the photocatalytic water splitting hydrogen production performance diagram and the performance diagram of synergistic degradation of pollutants during hydrogen production of the NiS / CdS nanocomposite prepared in Specific Example 2 of the present invention under visible light excitation in the presence of different pollutants. Detailed Description of the Invention

[0018] This part will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The function of the accompanying drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation to the protection scope of the present invention.

[0019] A preferred embodiment of the present invention is a preparation method of a NiS / CdS photocatalytic water splitting and synergistic degradation of pollutants catalyst derived from Cd-PBA. This preparation method uses a simple two-step sulfidation method to derivatively prepare a NiS / CdS catalyst with a cubic core-shell structure from Cd-PBA as a precursor. First, the Cd-based Prussian blue analogue cube, that is, the Cd-PBA cube, is transformed into a cubic core-shell structure CdS, and then further transformed into a cubic core-shell structure NiS / CdS by adding a Ni source. The specific steps are as follows:

[0020] (1) Synthesis of Cd-PBA cubes: Dissolve 0.6 mmol of cadmium chloride, 1 g of PVP, and 0.35 mmol of sodium citrate in 20 mL of water to form solution A. Dissolve 0.4 mmol of K 3 [Co(CN) 6 in 20 mL of water to form solution B. Add solution B to solution A, then let the mixed solution stand and age for 1 h, centrifuge to collect the product, wash it 3 times with ethanol, and then ultrasonically disperse it in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution;

[0021] (2) Synthesis of cubic core-shell structure CdS: Dissolve 0.2 g of thioacetamide in a water-alcohol mixed solvent, then add it to the Cd-PBA cube solution to obtain a mixed solution C. Then add 100 - 300 μL of NH 3 ·H 2 O, NH3 ·H 2 The range of the amount of H₂O is 100 - 300 μL; after reacting for 30 min, the product was collected by centrifugation and washed 3 times with ethanol to obtain cubic core-shell structured CdS;

[0022] (3) Synthesis of cubic core-shell structured NiS / CdS: 0.6 g of thioacetamide and 600 μL of NH₃·H₂O were added to the cubic core-shell structured CdS, 3 ·H 2 O, after reacting for 1 h, 100 - 200 μL of 200 mM NiCl₂ 2 and 1 mL of 100 M Na₂S 2 were added, after reacting for 1 h, the product was collected by centrifugation, washed 3 times with ethanol, and then dried in an oven at 70 °C to obtain the cubic core-shell structured NiS / CdS catalyst. Specific Example 1

[0024] Synthesis of Cd-PBA cubes: 0.6 mmol of cadmium chloride, 1 g of PVP, and 0.35 mmol of sodium citrate were dissolved in 20 mL of water to form solution A, 0.4 mmol of K₃[Co(CN)₆] was dissolved in 20 mL of water to form solution B, solution B was added to solution A, and then the mixed solution was allowed to stand and age for 1 h. The product was collected by centrifugation, washed 3 times with ethanol, and then ultrasonically dispersed in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution; 3 [Co(CN)₆ 6 dissolved in 20 mL of water, a solution B was formed, solution B was added to solution A, and then the mixed solution was allowed to stand and age for 1 h. The product was collected by centrifugation, washed 3 times with ethanol, and then ultrasonically dispersed in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution;

[0025] Synthesis of cubic core-shell structured CdS: 0.2 g of thioacetamide was dissolved in a water-alcohol mixed solvent and then added to the Cd-PBA cube solution to obtain a mixed solution C. Then, 100 μL of NH₃·H₂O was added to the mixed solution C, 3 ·H 2 O, after reacting for 30 min, the product was collected by centrifugation, washed 3 times with ethanol to obtain cubic core-shell structured CdS;

[0026] Synthesis of cubic core-shell structured NiS / CdS: 0.6 g of thioacetamide and 600 μL of NH₃·H₂O were added to the cubic core-shell structured CdS, 3 ·H 2 O, after reacting for 1 h, 100 μL of 200 mM NiCl₂ 2 and 1 mL of 100 M Na₂S 2 were added, after reacting for 1 h, the product was collected by centrifugation, washed 3 times with ethanol, and then dried in an oven at 70 °C to obtain the cubic core-shell structured NiS / CdS catalyst. Specific Example 2

[0028] Synthesis of Cd-PBA cubes: Dissolve 0.6 mmol of cadmium chloride, 1 g of PVP, and 0.35 mmol of sodium citrate in 20 mL of water to form solution A. Dissolve 0.4 mmol of K 3 [Co(CN) 6 in 20 mL of water to form solution B. Add solution B to solution A, then let the mixed solution stand and age for 1 h. Centrifuge to collect the product, wash it 3 times with ethanol, and then ultrasonically disperse it in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution;

[0029] Synthesis of cubic core-shell structure CdS: Dissolve 0.2 g of thioacetamide in a water-alcohol mixed solvent, then add it to the Cd-PBA cube solution to obtain a mixed solution C. Then add 200 μL of NH 3 ·H 2 O to the mixed solution C. After reacting for 30 min, centrifuge to collect the product, wash it 3 times with ethanol to obtain cubic core-shell structure CdS;

[0030] Synthesis of cubic core-shell structure NiS / CdS: Add 0.6 g of thioacetamide and 600 μL of NH 3 ·H 2 O to the cubic core-shell structure CdS. After reacting for 1 h, add 150 μL of 200 mM NiCl 2 and 1 mL of 100M Na 2 S. After reacting for 1 h, centrifuge to collect the product, wash it 3 times with ethanol, and then dry it in an oven at 70 °C to obtain a cubic core-shell structure NiS / CdS catalyst.

[0031] Refer to Figure 1 - Figure 2 for Figure 1 the transmission electron microscope image of the NiS / CdS nanocomposite prepared in this specific example; Figure 2 This is the photocatalytic hydrogen production performance graph and the performance graph of synergistic degradation of pollutants during hydrogen production of the NiS / CdS nanocomposite prepared in Specific Example 2 under visible light excitation in the presence of different pollutants. Specific Example 3

[0033] Synthesis of Cd-PBA cubes: Dissolve 0.6 mmol of cadmium chloride, 1 g of PVP, and 0.35 mmol of sodium citrate in 20 mL of water to form solution A. Dissolve 0.4 mmol of K 3 [Co(CN) 6 in 20 mL of water to form solution B. Add solution B to solution A, then let the mixed solution stand and age for 1 h. Centrifuge to collect the product, wash it 3 times with ethanol, and then ultrasonically disperse it in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution;

[0034] Synthesis of cubic core-shell structured CdS: After dissolving 0.2 g of thioacetamide in a water-alcohol mixed solvent, it was added to the Cd-PBA cubic solution to obtain a mixed solution C. Then, 300 μL of NH 3 ·H 2 O was added thereto. After reacting for 30 min, the product was collected by centrifugation and washed 3 times with ethanol to obtain cubic core-shell structured CdS;

[0035] Synthesis of cubic core-shell structured NiS / CdS: 0.6 g of thioacetamide and 600 μL of NH 3 ·H 2 O were added to the cubic core-shell structured CdS. After reacting for 1 h, 200 μL of 200 mM NiCl 2 and 1 mL of 100M Na 2 S were added. After reacting for 1 h, the product was collected by centrifugation, washed 3 times with ethanol, and then dried in an oven at 70 °C to obtain the cubic core-shell structured NiS / CdS catalyst.

[0036] The NiS / CdS nanocomposite prepared by the present invention can effectively decompose water to produce hydrogen under visible light excitation and synergistically degrade pollutants, thereby achieving the effect of synergistic enhancement of new energy production for treating pollutants.

[0037] The NiS / CdS nanocomposite prepared by the present invention has a regular hollow core-shell structure, is simple to prepare, has a low cost, and is suitable for large-scale popularization and application. On the premise of no conflict, those skilled in the art can freely combine and superimpose the above-mentioned additional technical features.

[0038] The above is only the preferred implementation mode of the present invention. As long as the technical solutions that achieve the purpose of the present invention by basically the same means fall within the protection scope of the present invention.

Claims

1. Preparation method of NiS / CdS photocatalytic water splitting and co-degrading pollutant catalyst derived from Cd-PBA, characterized in that: The preparation method uses a simple two-step sulfidation method to derivatively prepare a NiS / CdS catalyst with a cubic core-shell structure from Cd-PBA as a precursor; first, a Cd-based Prussian blue analogue cube, i.e., a Cd-PBA cube, is converted into a cubic core-shell structure CdS, and then further converted into a cubic core-shell structure NiS / CdS by adding a Ni source. The specific steps are as follows: (1) Synthesis of Cd-PBA cubes: 0.6 mmol of cadmium chloride, 1 g of PVP, and 0.35 mmol of sodium citrate were dissolved in 20 mL of water to form solution A. 0.4 mmol of K 3 [Co(CN) 6 was dissolved in 20 mL of water to form solution B. Solution B was added to solution A. Then, the mixed solution was allowed to stand and age for 1 h. The product was collected by centrifugation, washed three times with ethanol, and then ultrasonically dispersed in a mixed solution of 50 mL of water and 50 mL of ethanol to obtain a Cd-PBA cube solution; (2) Synthesis of cubic core-shell structured CdS: After dissolving 0.2 g of thioacetamide in a water-alcohol mixed solvent, it was added to the Cd-PBA cubic solution to obtain a mixed solution C. Then, a certain amount of NH 3 ·H 2 O was added. After reacting for 30 min, the product was collected by centrifugation and washed 3 times with ethanol to obtain cubic core-shell structured CdS; (3) Synthesis of Cubic Core-Shell Structure NiS / CdS: 0.6 g of thioacetamide and 600 μL of NH 3 ·H 2 O were added to the cubic core-shell structure CdS. After reacting for 1 h, a certain amount of 200 mM NiCl 2 and 1 mL of 100 M Na 2 S were added. After reacting for 1 h, the product was collected by centrifugation, washed three times with ethanol, and then dried in an oven at 70 °C to obtain the cubic core-shell structure NiS / CdS catalyst.

2. The preparation method of NiS / CdS photocatalytic water splitting and co-degrading pollutant catalyst derived from Cd-PBA according to claim 1, characterized in that: The amount of NH 3 ·H 2 O added in step (2) ranges from 100 to 300 μL.

3. The preparation method of NiS / CdS photocatalytic water splitting and co-degrading pollutant catalyst derived from Cd-PBA according to claim 1, characterized in that: The amount of 200 mM NiCl added in step (3) 2 ranges from 100 to 200 μL.

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