Fe2O3 / MoNiP photo-anode thin film with high stability and preparation method and application of Fe2O3 / MoNiP photo-anode thin film

Abstract

The invention belongs to the technical field of photoelectrochemistry, and particularly discloses a Fe2O3 / MoNiP photo-anode film with high stability and a preparation method and application thereof. MoNiP is generated on Fe2O3 in situ through a chemical plating method, and the Fe2O3 / MoNiP composite photo-anode film is constructed. The composite material shows remarkable photoelectrochemical activity and long-term stability in a solar water decomposition reaction, the photoelectrochemical efficiency can be effectively improved, and the problems that a traditional Fe2O3 material is low in catalytic activity and poor in stability are solved. The material is widely applicable to solar-driven hydrogen production, and has good economical efficiency and industrial application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of photoelectrochemical technology, and particularly relates to an Fe2O3 / MoNiP photoanode thin film with high stability, a preparation method thereof, and an application thereof. Background Art

[0002] With the increasing severity of energy crisis and environmental problems, it has become crucial to develop clean and efficient energy conversion technologies. Photoelectrochemical technology is considered to be one of the important technologies for future clean energy because it can directly utilize solar energy and convert it into chemical energy. Especially in the field of photoanodes (i.e., solar water splitting catalysts), finding highly efficient and stable catalytic materials has always been the focus of research.

[0003] Fe2O3 has received extensive attention in photoelectrochemistry due to its rich resources, good stability, and low cost. However, Fe2O3 has problems of low catalytic efficiency and significant decline in catalytic activity over time in practical applications. Therefore, improving the stability and photoelectrochemical efficiency of Fe2O3 is an important research direction at present.

[0004] To overcome the disadvantages of Fe2O3 in photoelectrochemical applications, it has become an effective strategy to use transition metals such as Mo, Ni, and P to form catalysts with excellent properties. MoNiP is a promising electrocatalytic material with good conductivity and stability, but it cannot be used alone as a photoelectrochemical material. Therefore, combining Fe2O3 with MoNiP is expected to obtain a photoanode with better photoelectrochemical performance and higher stability. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a preparation method and an application of an Fe2O3 / MoNiP photoanode thin film with high stability. By precisely controlling the preparation processes of Fe2O3 and MoNiP, a novel photoanode material is obtained, which exhibits excellent stability and photoelectrochemical activity in the water splitting reaction.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A preparation method of an Fe2O3 / MoNiP photoanode thin film with high stability includes the following steps:

[0008] 1) Dissolve a molybdenum source, a nickel source, a phosphorus source, a complexing agent, and a buffering agent in deionized water to obtain an electroplating solution;

[0009] 2) Place the reaction vessel containing the electroplating solution in a constant temperature drying oven, immerse the Fe2O3 photoanode thin film in the reaction vessel, and carry out the reaction; during the reaction, replace the electroplating solution once every hour;

[0010] 3) After the reaction is completed, take out the sample and carefully rinse it with pure water. After drying, the Fe2O3 / MoNiP photoanode film is obtained.

[0011] Furthermore, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 2), the preparation method of the Fe2O3 photoanode film includes the following steps:

[0012] 1) Dissolve ferric chloride hexahydrate and urea in deionized water, add TiCl4 ethanol solution dropwise, and stir well to prepare a precursor solution;

[0013] 2) Place the precursor solution and the cleaned FTO conductive glass in a hydrothermal autoclave, and hydrothermally react at 100 °C for 12 h to obtain a Ti-FeOOH film;

[0014] 3) Calcinate the Ti-FeOOH film in a muffle furnace at 550 °C for 2 h to obtain the Fe2O3 photoanode film.

[0015] Even further, in the preparation method of the above-mentioned Fe2O3 photoanode film, in step 1), the mass of ferric chloride hexahydrate is 0.81 g, the mass of urea is 0.18 g, the amount of deionized water used is 20 mL, the volume concentration of the TiCl4 ethanol solution is 5%, and the amount used is 150 μL.

[0016] Furthermore, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 1), the molybdenum source is sodium molybdate, and the mass is 0.2 g.

[0017] Furthermore, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 1), the nickel source is nickel sulfate hexahydrate, and the mass is 2.5 g.

[0018] Furthermore, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 1), the phosphorus source is sodium dihydrogen phosphate, and the mass is 3 g.

[0019] Furthermore, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 1), the amount of deionized water used is 100 mL.

[0020] Furthermore, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 1), the complexing agent is sodium citrate, and the mass is 1.5 g.

[0021] Further, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 1), the buffer is ammonium sulfate with a mass of 1.5 g.

[0022] Further, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 2), the content of the electroplating solution in the reaction vessel is 20 mL.

[0023] Further, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 2), the temperature of the constant temperature drying oven is set at 50 °C.

[0024] Further, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 2), the reaction time is 1.5 h.

[0025] Further, in the preparation method of the above-mentioned Fe2O3 / MoNiP photoanode film with high stability, in step 3), the drying temperature is 50 °C.

[0026] Application of the Fe2O3 / MoNiP photoanode film with high stability described in any one of the above in photoelectrochemical water splitting for hydrogen production.

[0027] The beneficial effects of the present invention are:

[0028] 1. The Fe2O3 / MoNiP photoanode film provided by the present invention greatly improves the stability of Fe2O3 in long-term photoelectrochemical reactions.

[0029] 2. The preparation method of the Fe2O3 / MoNiP photoanode film provided by the present invention has a simple production process and broad application prospects.

[0030] 3. The photocurrent and stability of the Fe2O3 / MoNiP photoanode film provided by the present invention have both been improved. Description of the Drawings

[0031] Figure 1 It is a comparison chart of XRD of the Fe2O3 / MoNiP photoanode film prepared in Example 2 and the Fe2O3 film prepared in Example 1.

[0032] Figure 2 It is a comparison chart of LSV of the Fe2O3 / MoNiP photoanode film prepared in Example 2 and the Fe2O3 film prepared in Example 1.

[0033] Figure 3Comparison chart of the stability of the Fe2O3 / MoNiP photoanode film prepared in Example 2 and the Fe2O3 film prepared in Example 1.

[0034] Figure 4 Hydrolysis rate chart of the Fe2O3 / MoNiP photoanode film prepared in Example 2 and the Fe2O3 film prepared in Example 1. Detailed implementation manners

[0035] Example 1: Fe2O3 photoanode film

[0036] 1) Dissolve 0.81 g of ferric chloride hexahydrate and 0.18 g of urea in 20 mL of deionized water, and add 150 μL of a 5% (by volume) TiCl4 ethanol solution, then stir well to prepare a precursor solution.

[0037] 2) Place the precursor solution and the cleaned FTO conductive glass in a 100 mL hydrothermal autoclave, and hydrothermally react at 100 °C for 12 h to obtain a Ti-FeOOH film.

[0038] 3) Calcinate the Ti-FeOOH film in a muffle furnace at 550 °C for 2 h to obtain the Fe2O3 photoanode film.

[0039] Example 2: Fe2O3 / MoNiP photoanode film with high stability

[0040] (I) Preparation method

[0041] 1) Dissolve 2.5 g of nickel sulfate hexahydrate, 1.5 g of ammonium sulfate, 1.5 g of sodium citrate, 3 g of sodium dihydrogen phosphate, and 0.2 g of sodium molybdate in 100 mL of deionized water for use as an electroplating solution.

[0042] 2) Take 20 mL of the electroplating solution in a reaction vessel and preheat it in a 50 °C constant temperature drying oven. Immerse the Fe2O3 photoanode film prepared in Experimental Example 1 in the reaction vessel for 1.5 h; during the reaction, replace the electroplating solution once every hour to ensure the uniformity and stability of the reaction.

[0043] 3) After the reaction is completed, take out the sample and carefully rinse it with pure water, and dry it at 50 °C to obtain the Fe2O3 / MoNiP photoanode film.

[0044] (II) Detection

[0045] Figure 1 Comparison chart of the XRD of the Fe2O3 / MoNiP photoanode film prepared in Example 2 and the Fe2O3 film prepared in Example 1. From Figure 1It can be seen that the diffraction peaks of Fe2O3 / MoNiP correspond to the diffraction peaks of SnO2 (FTO) (PDF#46-1088) and Fe2O3 (PDF#33-0664), respectively. Due to the detection limit of XRD, MoNiP was not detected, which also indicates that the loading of MoNiP did not change the crystal structure of Fe2O3.

[0046] Application of Example 3

[0047] The Fe2O3 and Fe2O3 / MoNiP photoanode thin films prepared in Examples 1 and 2 were respectively subjected to performance tests such as LSV, stability, and water splitting.

[0048] All electrochemical experiment tests were carried out in an electrochemical workstation (Princeton Applied Research 2273) with a three-electrode system. The sample thin film was used as the working electrode, a platinum sheet was used as the counter electrode, Ag / AgCl was used as the reference electrode, the electrolyte was 1M potassium hydroxide, and the light irradiation area of the sample was 1 cm 2 , and the water splitting test used GC-1690 to detect the hydrogen production amount in each period.

[0049] LSV test: The light source was a 300W xenon lamp, and the measured results are as Figure 2 shown. The results show that the photocurrent density of the Fe2O3 / MoNiP photoanode thin film is much larger than that of Fe2O3, indicating that the photoelectrochemical performance has been improved after loading MoNiP.

[0050] Stability test: The light source was selected as a 300W xenon lamp, and the bias voltage was 1.23V vs. RHE. The measured results are as Figure 3 shown. After forming Fe2O3 / MoNiP by loading MoNiP on Fe2O3, the photocurrent density of the Fe2O3 / MoNiP photoanode thin film did not decrease significantly after 5h of testing, while that of Fe2O3 decreased significantly, indicating that the loading of MoNiP significantly improved the stability.

[0051] Water splitting hydrogen production test: The light source was selected as a 300W xenon lamp, and the bias voltage was 1.23V vs. RHE. The measured results are as Figure 4 shown. After loading MoNiP, the hydrogen production rate value of the Fe2O3 / MoNiP photoanode thin film is greater than that of Fe2O3, proving that Fe2O3 / MoNiP has a more effective water oxidation driving force.

Claims

1. A Fe2O3 / MoNiP photoanode film with high stability, characterized in that: The preparation method thereof comprises the following steps: 1) dissolving a molybdenum source, a nickel source, a phosphorus source, a complexing agent and a buffer in deionized water to prepare an electroplating solution; 2) placing a reaction container containing the electroplating solution in a constant temperature drying oven, immersing the Fe2O3 photoanode film in the reaction container, and reacting; during the reaction process, the electroplating solution is replaced once every hour; 3) After the reaction is completed, the sample is taken out and carefully rinsed with pure water, and then dried to obtain the Fe2O3 / MoNiP photoanode film.

2. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 2), the method for preparing the Fe2O3 photoanode film comprises the following steps: 1) Dissolve ferric chloride hexahydrate and urea in deionized water, add TiCl4 ethanol solution dropwise, and stir well to prepare a precursor solution; 2) Place the precursor solution and the cleaned FTO conductive glass in a hydrothermal reactor and hydrothermal at 100°C for 12 hours to obtain a Ti-FeOOH film; 3) The Ti-FeOOH film was calcined at 550°C in a muffle furnace for 2 h to obtain a Fe2O3 photoanode film.

3. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 2, characterized in that: In step 1), the mass of ferric chloride hexahydrate is 0.81 g, the mass of urea is 0.18 g, the amount of deionized water is 20 mL, the volume concentration of TiCl4 ethanol solution is 5%, and the amount is 150 μL.

4. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 1), the molybdenum source is sodium molybdate with a mass of 0.2 g; the nickel source is nickel sulfate hexahydrate with a mass of 2.5 g; the phosphorus source is sodium dihydrogen phosphate with a mass of 3 g; and the amount of deionized water used is 100 mL.

5. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 1), the complexing agent is sodium citrate, with a mass of 1.5 g.

6. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 1), the buffer is ammonium sulfate, with a mass of 1.5 g.

7. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 2), the electroplating solution content in the reaction container is 20 mL.

8. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 2), the temperature of the constant temperature drying oven is set to 50° C., and the reaction time is 1.5 h.

9. The Fe2O3 / MoNiP photoanode film with high stability as claimed in claim 1, characterized in that: In step 3), the drying temperature is 50°C.

10. Use of the highly stable Fe2O3 / MoNiP photoanode film according to any one of claims 1 to 9 in photoelectrochemical water decomposition to produce hydrogen.

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