Preparation method of hof / cd s photocatalyst and application of the photocatalyst in photocatalytic decomposition of water

Abstract

The application relates to the technical field of nanocomposite photocatalytic material preparation, and discloses a preparation method of HOF / CdS photocatalyst and application of the HOF / CdS photocatalyst in photocatalytic decomposition of water, and the specific preparation method is as follows: CdS photocatalyst is prepared by using Cd(NO3)2*4H2O and NH2CSNH2 through a solvothermal method; the CdS photocatalyst and H4TCBP are dissolved in a mixed solution of an organic solvent and deionized water, stirring, centrifugal treatment and precipitation are carried out; the precipitation is subjected to multiple centrifugal treatments by using ethanol and acetone, and the HOF / CdS photocatalyst is obtained. The prepared photocatalytic material has good photocatalytic hydrogen production activity, and the preparation method is simple and easy to operate.

Description

Technical Field

[0001] This invention relates to the field of nanocomposite photocatalytic material preparation technology, and in particular to a method for preparing HOF / CdS photocatalyst and its application in photocatalytic water splitting. Background Technology

[0002] CdS semiconductors have attracted widespread attention in the fields of energy and photocatalysis. With a band gap of approximately 2.42 eV, it can utilize visible light and exhibits excellent photocatalytic hydrogen production performance. Furthermore, CdS possesses suitable band positions, a large specific surface area, and low preparation cost, making it a highly sought-after photocatalytic material. However, CdS exhibits significant photocorrosion, and photogenerated electrons and holes readily recombine, which reduces the efficiency of photocatalytic hydrogen production, causing a discrepancy between its performance and theoretical values. Summary of the Invention

[0003] Objective of the Invention: To address the problems existing in the prior art, this invention provides a method for preparing HOF / CdS photocatalysts and their application in photocatalytic water splitting. A CdS photocatalyst is prepared via a solvothermal method, and then HOF and the CdS photocatalyst are combined to obtain the HOF / CdS photocatalyst. The HOF / CdS photocatalyst prepared by this invention exhibits good photocatalytic hydrogen production activity, and the preparation method is simple and easy to operate.

[0004] Technical solution: This invention provides a method for preparing HOF / CdS photocatalyst, comprising the following steps:

[0005] S1: CdS photocatalyst was prepared by solvothermal method using Cd(NO3)2∙4H2O and NH2CSNH2; the reaction was carried out in a reactor at 150-180 ℃ for 20-25 h;

[0006] S2: Dissolve the CdS photocatalyst and H4TCBP in a mixed solution of organic solvent and deionized water, stir, centrifuge, and collect the precipitate;

[0007] S3: The precipitate was washed several times with ethanol and acetone respectively to obtain the HOF / CdS photocatalyst.

[0008] Furthermore, in S1, the mass ratio of Cd(NO3)2∙4H2O to NH2CSNH2 is 4.5-5.0∶3.0-4.0.

[0009] Furthermore, in S1, the solvent used in the solvothermal method is ethylenediamine.

[0010] Furthermore, the volume of the ethylenediamine is 80-90 ml.

[0011] Furthermore, in S2, the mass ratio of the CdS photocatalyst to H4TCBP is 1:1 to 12:1.

[0012] Furthermore, in S2, the organic solvent is DMF.

[0013] Furthermore, the volume of the DMF is 2-5 ml.

[0014] Furthermore, in S2, the specific conditions for the centrifugation treatment are: a rotation speed of 10,000-12,000 r and a centrifugation time of 10-20 min;

[0015] In S3, the specific conditions for centrifugation are: rotation speed of 10000-12000 r and centrifugation time of 10-20 min.

[0016] Preferably, in step S2, the stirring time is 5-10 minutes.

[0017] The present invention also provides the application of the HOF / CdS photocatalyst prepared by any of the above methods in photocatalytic water splitting for hydrogen production.

[0018] Beneficial Effects: A CdS photocatalyst was prepared via a simple solvothermal method. Then, HOF and CdS were composited using organic solvent dissolution, stirring, and centrifugation to obtain an HOF / CdS photocatalyst. Under light irradiation, CdS and HOF are excited to generate photogenerated electrons and holes. The Eo of HOF... CB Photogenerated electrons on the surface can be transferred to the E-phase of CdS through the formed heterojunction. CB Up, so that the protons (H) in the water + CdS is reduced to H2. Furthermore, the E2 of CdS... VB Photogenerated holes on the surface can migrate to the E of the HOF. VB The electrons and holes are absorbed by Na₂SO₃ and Na₂S, thus improving the separation efficiency of photogenerated electrons and holes, extending the lifetime of photogenerated charges, and enhancing the photocatalytic activity for hydrogen production. This synthesis method has the advantages of simple operation and ease of industrial production. Attached Figure Description

[0019] Figure 1 The hydrogen production rate graphs are for the HOF / CdS photocatalysts prepared in Examples 1-3 and the CdS photocatalysts prepared in the comparative example. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the embodiments.

[0021] Implementation method 1:

[0022] This embodiment provides a method for preparing HOF / CdS photocatalyst, the specific steps of which are as follows:

[0023] Step 1: 4.66 g of Cd(NO3)2∙4H2O and 3.45 g of NH2CSNH2 were reacted in a reactor at 160 °C for 24 h using ethylenediamine (84 ml) as a solvent via a simple solvothermal method to synthesize CdS photocatalyst.

[0024] Step 2: Mix 20 ml of deionized water with 3 ml of organic solvent DMF to obtain a mixed solution; dissolve 20 mg of H4TCBP and 40 mg of CdS in the mixed solution, stir for 5 min, then add 17 mL of ethanol, centrifuge at 12000 r for 15 min, and wash several times with ethanol and acetone respectively to obtain HOF / CdS-2 photocatalyst.

[0025] Implementation Method 2:

[0026] This embodiment provides a method for preparing HOF / CdS photocatalyst, the specific steps of which are as follows:

[0027] Step 1: 4.66 g of Cd(NO3)2∙4H2O and 3.45 g of NH2CSNH2 were reacted in a reactor at 160 °C for 24 h using ethylenediamine (84 ml) as a solvent via a simple solvothermal method to synthesize CdS photocatalyst.

[0028] Step 2: Mix 20 ml of deionized water with 3 ml of organic solvent DMF to obtain a mixed solution; dissolve 20 mg of H4TCBP and 100 mg of CdS in the mixed solution, stir for 5 min, then add 17 mL of ethanol, centrifuge at 12000 r for 15 min, and wash several times with ethanol and acetone respectively to obtain HOF / CdS-5 photocatalyst.

[0029] Implementation Method 3:

[0030] This embodiment provides a method for preparing HOF / CdS photocatalyst, the specific steps of which are as follows:

[0031] Step 1: 4.66 g of Cd(NO3)2∙4H2O and 3.45 g of NH2CSNH2 were reacted in a reactor at 160 °C for 24 h using ethylenediamine (84 ml) as a solvent via a simple solvothermal method to synthesize CdS photocatalyst.

[0032] Step 2: Mix 20 ml of deionized water with 3 ml of organic solvent DMF to obtain a mixed solution; dissolve 20 mg of H4TCBP and 200 mg of CdS in the mixed solution, stir for 5 min, then add 17 mL of ethanol, centrifuge at 12000 r for 15 min, and wash several times with ethanol and acetone respectively to obtain HOF / CdS-10 photocatalyst.

[0033] Comparative example:

[0034] 4.66 g of Cd(NO3)2∙4H2O and 3.45 g of NH2CSNH2 were reacted in a reactor at 160 °C for 24 h using ethylenediamine (84 ml) as a solvent via a simple solvothermal method to obtain the CdS photocatalyst.

[0035] Material characterization and performance testing:

[0036] The performance of the HOF / CdS photocatalyst prepared in this invention was analyzed, and the results are as follows:

[0037] Figure 1 This graph shows the hydrogen production rates of CdS photocatalyst, HOF / CdS-2 photocatalyst, HOF / CdS-5 photocatalyst, and HOF / CdS-10 photocatalyst. The HOF / CdS-5 photocatalyst exhibits the highest hydrogen production rate at 1178.28 μmol / g. -1 h -1 It is 2.64 times that of pure CdS photocatalyst.

[0038] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a HOF / CdS photocatalyst, characterized in that: Includes the following steps: S1: CdS photocatalyst was prepared by solvothermal method using Cd(NO3)2∙4H2O and NH2CSNH2; the reaction was carried out in a reactor at 150-180 ℃ for 20-25 h; S2: Dissolve the CdS photocatalyst and H4TCBP in a mixed solution of organic solvent and deionized water, stir, centrifuge, and collect the precipitate; S3: The precipitate was washed several times with ethanol and acetone respectively to obtain the HOF / CdS photocatalyst.

2. The method for preparing the HOF / CdS photocatalyst according to claim 1, characterized in that: In S1, the mass ratio of Cd(NO3)2∙4H2O to NH2CSNH2 is 4.5-5.0∶3.0-4.

0.

3. The method for preparing the HOF / CdS photocatalyst according to claim 1, characterized in that: In S1, the solvent used in the solvothermal method is ethylenediamine.

4. The method for preparing the HOF / CdS photocatalyst according to claim 3, characterized in that: The volume of the ethylenediamine is 80-90 ml.

5. The method for preparing the HOF / CdS photocatalyst according to claim 1, characterized in that: In S2, the mass ratio of the CdS photocatalyst to H4TCBP is 1:1-12:

1.

6. The method for preparing the HOF / CdS photocatalyst according to claim 1, characterized in that: In S2, the organic solvent is DMF.

7. The method for preparing the HOF / CdS photocatalyst according to claim 6, characterized in that: The volume of the DMF is 2-5 ml.

8. The method for preparing the HOF / CdS photocatalyst according to claim 1, characterized in that: In S2, the specific conditions for centrifugation are: rotation speed of 10000-12000 r and centrifugation time of 10-20 min; In S3, the specific conditions for centrifugation are: rotation speed of 10000-12000 r and centrifugation time of 10-20 min.

9. The method for preparing the HOF / CdS photocatalyst according to claim 1, characterized in that: In S2, the stirring time is 5-10 min.

10. The application of a HOF / CdS photocatalyst prepared by any one of claims 1-9 in photocatalytic water splitting for hydrogen production.

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