Photoelectrocatalyst, preparation method and application thereof

Abstract

The application provides a photoelectric catalyst and a preparation method and application thereof, and relates to the technical field of catalysts.A preparation method of a photoelectric catalyst comprises the following steps: S1, uniformly mixing water, a copper source, an indium source and PVP to obtain a spinning solution; performing electrostatic spinning on the spinning solution, and sintering to obtain an intermediate 1; S2, introducing a sulfur source into the intermediate 1 to perform chemical vapor deposition to obtain an intermediate 2; and S3, introducing a phosphorus source and a sulfur source into the intermediate 2 to perform chemical vapor deposition to obtain the photoelectric catalyst.The photoelectric catalyst provided by the application can further improve the water decomposition performance under ultrasonic conditions, and the photoelectric catalyst can also be applied to a zinc-air battery, so that the zinc-air battery has good electrochemical performance.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a photoelectrocatalyst, its preparation method, and its application. Background Technology

[0002] Metal-air batteries, such as zinc-air batteries (ZAB), have a much higher theoretical energy density (1086 Wh / kg) compared to mainstream lithium-ion batteries, and also offer advantages such as environmental friendliness and low cost. However, their performance is limited by the slow bifunctional reaction kinetics of oxygen reduction (ORR) and oxygen evolution (OER) at the oxygen electrode. If photoelectrocatalysts could be used simultaneously to catalyze the oxygen reduction reaction, making them excellent multifunctional catalysts for HER, OER, and ORR, it would directly change the current landscape of electrocatalysts.

[0003] CuInP2S6, as a van der Waals layered ferroelectric material, possesses both a direct wide bandgap (~2.9 eV) and out-of-plane polarization, effectively promoting photogenerated carrier separation and suppressing recombination, thus showing broad application prospects in the field of photoelectrocatalysis. However, balancing the integrity of fiber morphology and the purity of crystal structure is a major challenge in the preparation of CuInP2S6 nanofibers. Conventional electrospinning combined with one-step sulfurization / phosphating treatment often leads to fiber breakage, excessive grain growth, or the formation of impurity phases such as CuInS2 and InP due to uneven reaction rates, making it difficult to obtain CuInP2S6 nanofibers with high crystallinity and uniform morphology. Summary of the Invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a photoelectrocatalyst, its preparation method and application.

[0005] The photoelectrocatalyst proposed in this invention is a CuInP2S6 nanofiber material.

[0006] CuInP2S6 is a van der Waals layered ferroelectric material with a direct wide bandgap (~2.9 eV), enabling efficient absorption of visible light and generation of photogenerated carriers. Its out-of-plane polarization effectively promotes carrier separation and inhibits recombination, thereby improving photoelectric conversion efficiency and promoting electrocatalysis. Furthermore, CuInP2S6 exhibits piezoelectric properties, further enhancing interfacial charge transport and catalytic activity under external stress, such as ultrasonic conditions. Its ferroelectric polarization can be modulated by external electric fields or interfacial strain to optimize performance. Compared to traditional bulk materials, CIPS nanosheet arrays possess high specific surface area and abundant active sites, significantly improving light absorption and reaction kinetics. Simultaneously, their atomically flat interfaces reduce defect-induced carrier loss, providing an ideal platform for designing efficient and stable photocatalysts.

[0007] This invention also proposes a method for preparing a photoelectrocatalyst, comprising the following steps:

[0008] S1. Mix water, copper source, indium source and PVP evenly to obtain spinning solution; electrospin the spinning solution and sinter it to obtain intermediate 1.

[0009] S2. A sulfur source is introduced into intermediate 1 for chemical vapor deposition to obtain intermediate 2;

[0010] S3. Phosphorus and sulfur sources are introduced into intermediate 2 for chemical vapor deposition to obtain a photoelectrophotocatalyst.

[0011] This invention prepares a multifunctional photocatalyst of ferroelectric CuInP2S6 nanofibers using electrospinning and chemical vapor deposition. The material exhibits good photocatalytic activity and stability.

[0012] Preferably, in S1, the mass ratio of water, copper source, indium source, and PVP is (5-20):(0.2-0.8):(0.3-0.9):(0.5-3).

[0013] More preferably, the mass ratio of water, copper source, indium source and PVP is (5-15):(0.2-0.4):(0.4-0.8):(1-2).

[0014] More preferably, the mass ratio of water, copper source, indium source, and PVP is 10:0.37:0.58:1.8.

[0015] The mass ratio of water, copper source, indium source, and PVP within a certain range helps to form a spinning solution, thus preparing CuInO2 nanofiber materials.

[0016] Preferably, in S1, the molecular weight of PVP is 1 million to 1.5 million.

[0017] Preferably, in S1, the parameters of electrospinning include: the flow rate of the spinning solution is 0.2 to 1 mL / min, the applied positive voltage is 10 to 30 kV, and the negative voltage is -5 to -1 kV.

[0018] More preferably, the electrospinning process includes a syringe and a receiver. The syringe is a plastic syringe with a stainless steel needle, and the receiver is selected from one or more of aluminum foil, copper foil, tin foil, and ITO conductive glass. The distance between the syringe needle and the receiver is 5 to 20 cm.

[0019] Controlling the parameters of electrospinning ensures that the fiber diameter is uniform, the surface is smooth, and there are no defects such as beads or droplets, thereby obtaining nanofiber membranes with good morphology and controllable distribution.

[0020] Preferably, in S1, sintering includes heating to 300-800°C at a heating rate of 1-5°C / min and sintering for 1-5 hours.

[0021] Within a certain range, sintering parameters help to balance the contradictions between the removal of organic matter, the formation of crystal phases, and the maintenance of fiber morphology, so that the sintering process is maintained at a level that ensures that organic matter is completely removed, grains do not grow excessively, and fiber morphology is not destroyed.

[0022] Preferably, in S1, the copper source is selected from one or more of copper acetate, copper nitrate, copper sulfate, and copper chloride.

[0023] Preferably, in S1, the indium source is selected from one or more of indium acetate, indium nitrate, indium sulfate, and indium chloride.

[0024] The selection of copper and indium sources helps to achieve precise control of stoichiometry, optimization of fiber morphology, reduction of sintering temperature, improvement of product purity, and stable and repeatable process.

[0025] Preferably, in S1, intermediate 1 is CuInO2 nanofiber material.

[0026] Preferably, in S2, the sulfur source is selected from one or more of sulfur powder, thioacetamide, thiourea, and ammonium sulfide.

[0027] Preferably, in S2, the mass ratio of intermediate 1 to sulfur source is (0.002~0.15):(0.01~0.5).

[0028] The mass ratio of intermediate 1 to sulfur source within a certain range helps to protect the nanofiber morphology of the precursor while ensuring complete sulfidation and obtaining high-purity CuInS2 material with the target stoichiometry, and prevents excessive grain growth that could lead to fiber morphology breakage.

[0029] Preferably, in step S2, introducing a sulfur source into intermediate 1 for chemical vapor deposition includes: placing the sulfur source upstream of a dual-temperature-controlled vacuum atmosphere tube furnace and placing intermediate 1 downstream of the dual-temperature-controlled vacuum atmosphere tube furnace; heating the upstream heating zone to 200-550°C at a heating rate of 1-5°C / min, and heating the downstream heating zone to 400-800°C at a heating rate of 5-15°C / min, with a holding time of 1-5 hours.

[0030] More preferably, the upstream heating zone and the downstream heating zone are heated simultaneously.

[0031] The role of chemical vapor deposition is to transform the original oxide nanofibers into CuInS2 nanofibers with novel semiconductor properties by a "displacement reaction" between a gaseous sulfur source and solid CuInO2 without damaging the nanofiber skeleton of the material.

[0032] Preferably, in step S2, a protective gas is introduced to purge air before chemical vapor deposition.

[0033] More preferably, the process of introducing protective gas and purging air before chemical vapor deposition includes: pumping the gas pressure in the dual-temperature-controlled vacuum atmosphere tube furnace to -0.1 MPa, then introducing protective gas into the dual-temperature-controlled vacuum atmosphere tube furnace until the gas pressure inside the furnace returns to atmospheric pressure, and then repeating the operation more than twice; the protective gas is selected from one or more of nitrogen and argon.

[0034] Preferably, in step S2, a protective gas is introduced during the chemical vapor deposition process. The flow rate of the protective gas is 20-100 sccm, and the protective gas is selected from one or more of nitrogen and argon.

[0035] More preferably, the flow rate of the protective gas is 25-50 sccm.

[0036] A protective gas flow rate within a certain range helps to precisely control the synthesis rate, improve the uniformity of the synthesized material, suppress defect formation, and improve the quality of the synthesized material.

[0037] Preferably, in S3, the mass ratio of intermediate 2, phosphorus source, and sulfur source is (0.002~1.5):(0.01~0.5):(0.01~0.5).

[0038] The mass ratio of intermediate 2, phosphorus source, and sulfur source within a certain range helps to form a pure phase CuInP2S6 crystal structure, optimize crystal morphology and growth behavior, control the integrity of the layered structure, and achieve the target band structure and photoelectric properties.

[0039] Preferably, in S3, the sulfur source is selected from one or more of sulfur powder, thioacetamide, thiourea, and ammonium sulfide.

[0040] Preferably, in S3, the phosphorus source is selected from one or more of red phosphorus, sodium hypophosphite, white phosphorus, and phosphorus pentasulfide.

[0041] The selection of sulfur and phosphorus sources helps to form the target CuInP2S6 pure phase, control the reaction temperature, protect the morphology of nanofibers, accurately control the stoichiometry, regulate the electrical properties, optimize the reaction kinetics, and improve the crystallization quality.

[0042] Preferably, in step S3, introducing a phosphorus source and a sulfur source into the intermediate 2 for chemical vapor deposition includes: placing the phosphorus source and the sulfur source upstream of a dual-temperature-controlled vacuum atmosphere tube furnace, and placing the intermediate 2 downstream of the dual-temperature-controlled vacuum atmosphere tube furnace; heating the upstream heating zone to 200-500°C at a heating rate of 5-15°C / min, and heating the downstream heating zone to 300-800°C at a heating rate of 10-25°C / min, with a holding time of 0.5-5 hours.

[0043] More preferably, the upstream heating zone and the downstream heating zone are heated simultaneously.

[0044] Controlling the parameters of vapor deposition helps achieve the target stoichiometry and pure phase formation, regulate the morphology and structural integrity of nanofibers, improve crystallization quality and reduce defects, and enhance process repeatability and batch consistency.

[0045] Preferably, in step S3, a protective gas is introduced to purge air before chemical vapor deposition.

[0046] More preferably, the process of introducing protective gas and purging air before chemical vapor deposition includes: pumping the gas pressure in the dual-temperature-controlled vacuum atmosphere tube furnace to -0.1 MPa, then introducing protective gas into the dual-temperature-controlled vacuum atmosphere tube furnace until the gas pressure inside the furnace returns to atmospheric pressure, and then repeating the operation more than twice; the protective gas is selected from one or more of nitrogen and argon.

[0047] Preferably, in step S3, a protective gas is introduced during the chemical vapor deposition process. The flow rate of the protective gas is 20-100 sccm, and the protective gas is selected from one or more of nitrogen and argon.

[0048] More preferably, the flow rate of the protective gas is 50-100 sccm.

[0049] Within a certain range, the flow rate of the protective gas helps maintain a stable supersaturation in the reaction zone, thereby controlling the nucleation and growth process; it also allows the precursor vapor to diffuse uniformly across the entire nanofiber surface, resulting in a product with high crystallinity and uniform grain size; and it helps protect the intact morphology of the nanofibers.

[0050] Application of the above-described photocatalyst or the photocatalyst prepared by the above-described method in photocatalytic water splitting.

[0051] The photoelectrocatalyst prepared by this invention possesses both semiconductor and ferroelectric properties. When stimulated by external vibration, it can spontaneously generate additional current to assist the photoelectrocatalytic reaction, thereby further enhancing its photoelectrocatalytic water splitting performance.

[0052] Application of the above-described photoelectrocatalyst or the photoelectrocatalyst prepared by the above-described method in zinc-air batteries.

[0053] Preferably, the photoelectrocatalyst is used as a cathode catalyst in a zinc-air battery.

[0054] The photoelectrocatalyst provided by this invention serves as a cathode catalyst in zinc-air batteries, which helps to improve the various electrochemical performance characteristics of zinc-air batteries.

[0055] The beneficial effects of this invention are as follows:

[0056] This invention provides a simple, low-cost, and easily controllable method for preparing a multifunctional photocatalyst from ferroelectric CuInP2S6 nanofibers. The photocatalyst prepared by electrospinning and vapor deposition exhibits excellent photocatalytic water splitting performance, and its water splitting efficiency can be significantly improved under ultrasonic conditions to achieve higher energy conversion efficiency. Furthermore, this photocatalyst possesses good oxygen reduction performance and can be used as a cathode catalyst in zinc-air batteries to achieve excellent electrochemical performance. Attached Figure Description

[0057] Figure 1 The image shows the XRD pattern of the photoelectrocatalyst obtained in Example 2 of this invention.

[0058] Figure 2 This is a SEM image of the photoelectrocatalyst obtained in Example 2 of the present invention.

[0059] Figure 3 The image shows the TEM spectrum of the photoelectrocatalyst obtained in Example 2 of this invention.

[0060] Figure 4 The image shows the XPS spectrum of the photoelectrocatalyst obtained in Example 2 of this invention.

[0061] Figure 5 The Nyquist plot is of the photoelectrocatalyst obtained in Example 2 of this invention.

[0062] Figure 6 This is a graph showing the LSV curves of the photoelectrocatalyst obtained in Example 2 of the present invention under various conditions.

[0063] Figure 7 This is a time-current (it) curve of the photoelectrocatalyst obtained in Example 2 of the present invention under various conditions.

[0064] Figure 8 The graph shows the discharge polarization curve and power density curve of the battery when the photoelectrocatalyst obtained in Example 2 of the present invention is used as the air cathode catalyst of the zinc-air battery.

[0065] Figure 9 This is a specific capacity diagram of the battery when the photoelectrocatalyst obtained in Example 2 of the present invention is used as the air cathode catalyst of a zinc-air battery.

[0066] Figure 10 This is a step-like constant current discharge curve of the battery when the photoelectrocatalyst obtained in Example 2 of the present invention is used as the air cathode catalyst of the zinc-air battery. Detailed Implementation

[0067] The technical solution of the present invention will be described in detail through specific embodiments.

[0068] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0069] Example 1

[0070] A method for preparing a photoelectrocatalyst includes the following steps:

[0071] S1. Weigh 0.38g of copper acetate and place it in a 20mL beaker. Add 8mL of deionized water and stir for 1 hour to obtain a homogeneous solution. Then weigh 0.6g of indium acetate and add it to the above solution, stirring for 1 hour. Finally, measure 1g of PVP powder with a molecular weight of 1,300,000 and slowly add it to the above mixed solution, stirring for 10 hours to obtain the spinning solution. The spinning solution was loaded into a 10mL plastic syringe with a stainless steel needle (18G) and fixed on the sampler of the electrospinning device. The electrospun nanofibers were received using silicone paper. The flow rate of the electrospinning solution was set to 0.4mL / min. A positive voltage of 15kV and a negative voltage of -2kV were applied. The distance between the syringe needle and the collector was 12cm. The power was turned on to spin the nanofibers and obtain the precursor CuInO2 nanofiber membrane. The prepared precursor CuInO2 nanofiber membrane was placed in an oven and dried at 60℃ for 10h. Then it was placed in a 50mL crucible and sintered at high temperature in a muffle furnace. The heating rate was 3℃ / min, the holding temperature was 550℃, and the holding temperature was 3h to obtain CuInO2 nanofiber material.

[0072] S2. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. Before synthesis, 10 mg of sulfur powder was placed in a quartz boat in the upstream central heating zone of the tube furnace, and the CuInO2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 300 °C at a heating rate of 2 °C / min, while the downstream central heating zone was heated to 550 °C at atmospheric pressure at a heating rate of 4 °C / min, and held at this temperature for 2 hours. The argon flow rate of the gas path system was set to 25 sccm during the synthesis process. After the tube furnace cooled to room temperature, CuInS2 nanofiber material was obtained.

[0073] S3. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. 3 mg of red phosphorus and 5 mg of sulfur powder were placed in two quartz boats in the upstream central heating zone of the tube furnace, respectively. The CuInS2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 300 °C at a heating rate of 10 °C / min, while the downstream central heating zone was heated to 600 °C at atmospheric pressure at a heating rate of 15 °C / min, and held at this temperature for 2 hours. The argon flow rate of the gas path system was set to 50 sccm during the synthesis process. After the tube furnace cooled to room temperature, the ferroelectric CuInP2S6 nanofiber multifunctional photoelectrochemical catalyst material was obtained.

[0074] Example 2

[0075] A method for preparing a photoelectrocatalyst includes the following steps:

[0076] S1. Weigh 0.37g of copper acetate and place it in a 20mL beaker. Add 10mL of deionized water and stir for 1 hour to obtain a homogeneous solution. Then weigh 0.58g of indium acetate and add it to the above solution, stirring for 1 hour. Finally, measure 1.8g of PVP powder with a molecular weight of 1,300,000 and slowly add it to the above mixed solution, stirring for 12 hours to obtain the spinning solution. The spinning solution was loaded into a 10mL plastic syringe with a stainless steel needle (18G) and fixed on the sampler of the electrospinning device. The electrospun nanofibers were received using silicone paper. The flow rate of the electrospinning solution was set to 0.45mL / min. An 18.5kV positive voltage and a -3.5kV negative voltage were applied. The distance between the syringe needle and the collector was 14cm. The power was turned on to spin the nanofibers and obtain the precursor CuInO2 nanofiber membrane. The prepared precursor CuInO2 nanofiber membrane was placed in an oven and dried at 65℃ for 12h. Then it was placed in a 50mL crucible and sintered at high temperature in a muffle furnace. The heating rate was 2℃ / min, the holding temperature was 650℃, and the holding temperature was 2h to obtain CuInO2 nanofiber material.

[0077] S2. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. Before synthesis, 60 mg of sulfur powder was placed in a quartz boat in the upstream central heating zone of the tube furnace, and the CuInO2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 300 °C at a heating rate of 2 °C / min, while the downstream central heating zone was heated to 600 °C at atmospheric pressure at a heating rate of 5 °C / min, and held at this temperature for 2 hours. The argon flow rate of the gas path system was set to 25 sccm during the synthesis process. After the tube furnace cooled to room temperature, CuInS2 nanofiber material was obtained.

[0078] S3. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. 50 mg of red phosphorus and 40 mg of sulfur powder were placed in two quartz boats in the upstream central heating zone of the tube furnace, respectively. The CuInS2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 320 °C at a heating rate of 10 °C / min, while the downstream central heating zone was heated to 510 °C at atmospheric pressure at a heating rate of 20 °C / min, and held at this temperature for 1 hour. The argon flow rate of the gas path system was set to 50 sccm during the synthesis process. After the tube furnace cooled to room temperature, a ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst material was obtained, denoted as CuInP2S6-51060.

[0079] Example 3

[0080] A method for preparing a photoelectrocatalyst includes the following steps:

[0081] S1. Weigh 0.45g of copper acetate and place it in a 20mL beaker. Pour in 15mL of deionized water and stir for 1 hour to obtain a homogeneous solution. Then weigh 0.65g of indium acetate and add it to the above solution, stirring for 1 hour. Finally, measure 2.2g of PVP powder with a molecular weight of 1,300,000 and slowly add it to the above mixed solution, stirring for 12 hours to obtain the spinning solution. The spinning solution was loaded into a 10mL plastic syringe with a stainless steel needle (18G) and fixed on the sampler of the electrospinning device. The electrospun nanofibers were received using silicone paper. The flow rate of the electrospinning solution was set to 0.3mL / min. A positive voltage of 20kV and a negative voltage of -3kV were applied. The distance between the syringe needle and the collector was 15cm. The power was turned on to spin the nanofibers and obtain the precursor CuInO2 nanofiber membrane. The prepared precursor CuInO2 nanofiber membrane was placed in an oven and dried at 70℃ for 12h. Then it was placed in a 50mL crucible and sintered at high temperature in a muffle furnace. The heating rate was 4℃ / min, the holding temperature was 600℃, and the holding temperature was 2h to obtain CuInO2 nanofiber material.

[0082] S2. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. Before synthesis, 50 mg of sulfur powder was placed in a quartz boat in the upstream central heating zone of the tube furnace, and the CuInO2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 400 °C at a heating rate of 5 °C / min, while the downstream central heating zone was heated to 700 °C at atmospheric pressure at a heating rate of 8 °C / min, and held at this temperature for 3 hours. The argon flow rate of the gas path system was set to 25 sccm during the synthesis process. After the tube furnace cooled to room temperature, CuInS2 nanofiber material was obtained.

[0083] S3. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure inside the tube returned to atmospheric pressure. This operation was repeated twice. 50 mg of red phosphorus and 60 mg of sulfur powder were placed in two quartz boats in the upstream central heating zone of the tube furnace, respectively. The CuInS2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 300 °C at a heating rate of 6.5 °C / min, while the downstream central heating zone was heated to 550 °C at atmospheric pressure at a heating rate of 15 °C / min, and held at this temperature for 1 hour. The argon flow rate of the gas path system was set to 50 sccm during the synthesis process. After the tube furnace cooled to room temperature, a ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst material was obtained, denoted as CuInP2S6-55060.

[0084] Example 4

[0085] A method for preparing a photoelectrocatalyst includes the following steps:

[0086] S1. Weigh 0.72g of copper acetate and place it in a 20mL beaker. Pour in 15mL of deionized water and stir for 1 hour to obtain a homogeneous solution. Then weigh 0.85g of indium acetate and add it to the above solution, stirring for 1 hour. Finally, measure 2.5g of PVP powder with a molecular weight of 1,300,000 and slowly add it to the above mixed solution, stirring for 12 hours to obtain the spinning solution. The spinning solution was loaded into a 10mL plastic syringe with a stainless steel needle (18G) and fixed on the sampler of the electrospinning device. The electrospun nanofibers were received using silicone paper. The flow rate of the electrospinning solution was set to 0.65mL / min. A positive voltage of 25kV and a negative voltage of -4kV were applied. The distance between the syringe needle and the collector was 13cm. The power was turned on to spin the nanofibers and obtain the precursor CuInO2 nanofiber membrane. The prepared precursor CuInO2 nanofiber membrane was placed in an oven and dried at 65℃ for 12h. Then it was placed in a 50mL crucible and sintered at high temperature in a muffle furnace. The heating rate was 2℃ / min, the holding temperature was 650℃, and the holding temperature was 2h to obtain CuInO2 nanofiber material.

[0087] S2. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. Before synthesis, 400 mg of sulfur powder was placed in a quartz boat in the upstream central heating zone of the tube furnace, and the CuInO2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 400 °C at a heating rate of 10 °C / min, while the downstream central heating zone was heated to 800 °C at atmospheric pressure at a heating rate of 20 °C / min, and held for 1 hour. The argon flow rate of the gas path system was set to 25 sccm during the synthesis process. After the tube furnace cooled to room temperature, CuInS2 nanofiber material was obtained.

[0088] S3. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. 30 mg of red phosphorus and 50 mg of sulfur powder were placed in two quartz boats in the upstream central heating zone of the tube furnace, respectively. The CuInS2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 320 °C at a heating rate of 10 °C / min, while the downstream central heating zone was heated to 550 °C at atmospheric pressure at a heating rate of 20 °C / min, and held at this temperature for 1.5 h. The argon flow rate of the gas path system was set to 50 sccm during the synthesis process. After the tube furnace cooled to room temperature, a ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst material was obtained, denoted as CuInP2S6-55090.

[0089] Example 5

[0090] A method for preparing a photoelectrocatalyst includes the following steps:

[0091] S1. Weigh 0.47g of copper acetate and place it in a 20mL beaker. Add 12mL of deionized water and stir for 1 hour to obtain a homogeneous solution. Then weigh 0.63g of indium acetate and add it to the above solution, stirring for 1 hour. Finally, measure 1.3g of PVP powder with a molecular weight of 1,300,000 and slowly add it to the above mixed solution, stirring for 12 hours to obtain the spinning solution. The spinning solution was loaded into a 10mL plastic syringe with a stainless steel needle (18G) and fixed on the sampler of the electrospinning device. The electrospun nanofibers were received using silicone paper. The flow rate of the electrospinning solution was set to 0.38mL / min. A positive voltage of 14kV and a negative voltage of -1kV were applied. The distance between the syringe needle and the collector was 10cm. The power was turned on to spin the nanofibers and obtain the precursor CuInO2 nanofiber membrane. The prepared precursor CuInO2 nanofiber membrane was placed in an oven and dried at 65℃ for 12h. Then it was placed in a 50mL crucible and sintered at high temperature in a muffle furnace. The heating rate was 5℃ / min, the holding temperature was 500℃, and the holding temperature was 1.5h to obtain CuInO2 nanofiber material.

[0092] S2. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. Before synthesis, 10 mg of sulfur powder was placed in a quartz boat in the upstream central heating zone of the tube furnace, and the CuInO2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 550 °C at a heating rate of 10 °C / min, while the downstream central heating zone was heated to 700 °C at atmospheric pressure at a heating rate of 20 °C / min, and held for 3 hours. The argon flow rate of the gas path system was set to 25 sccm during the synthesis process. After the tube furnace cooled to room temperature, CuInS2 nanofiber material was obtained.

[0093] S3. Samples were synthesized using a dual-temperature-controlled vacuum atmosphere tube furnace. The gas pressure in the quartz tube of the dual-temperature-controlled vacuum atmosphere tube furnace was evacuated to -0.1 MPa using a gas pump. Argon gas was then introduced into the quartz tube until the pressure returned to atmospheric pressure. This process was repeated twice. 5 mg of red phosphorus and 70 mg of sulfur powder were placed in two quartz boats in the upstream central heating zone of the tube furnace, respectively. The CuInS2 nanofiber material was placed in the downstream central heating zone of the dual-temperature zone tube furnace. The upstream central heating zone was heated to 270 °C at a heating rate of 8 °C / min, while the downstream central heating zone was heated to 580 °C at atmospheric pressure at a heating rate of 16 °C / min, and held at this temperature for 2.5 h. The argon flow rate of the gas path system was set to 50 sccm during the synthesis process. After the tube furnace cooled to room temperature, the ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst material was obtained.

[0094] Photoelectrochemical performance testing: The ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst material prepared in the examples was spin-coated onto ITO conductive glass as the working electrode (area 1 cm²). 2 The photoelectrocatalytic hydrogen evolution and oxygen evolution performance were tested using Hg / HgO as the reference electrode and platinum wire as the auxiliary electrode. The photocatalytic performance was assessed in a 1M potassium hydroxide electrolyte environment. The photocatalytic testing system was equipped with a 300W xenon arc light source. The irradiance on the electrode surface was adjusted to the standard value of 100mW / cm² using a radiation intensity calibration device. The emission spectrum of the light source was modulated using an AM1.5G filter to match the solar spectral distribution. During testing, the electrolytic cell was placed in a water-filled ultrasonic machine with an ultrasonic power of 50W and a frequency of 40kHz. It curve tests were conducted under bias voltages of 1.23V vs. RHE and 0V vs. RHE, with the circuit being switched on and off every 10 seconds. The test results are shown below. Figure 7 As shown. The Nyquist test was set with a high frequency of 105 Hz, a low frequency of 0.1 Hz, and an amplitude of 5 mV. Electrochemical impedance spectroscopy curves were measured under illumination and without illumination. The test results are shown below. Figure 5 As shown in the figure. Linear sweep voltammetry (LSV) curves can describe the photoelectrocatalytic performance of a sample by showing the trend of sample current change with voltage. For the hydrogen evolution reaction test, a negative sweep (high voltage to low voltage) was used, and for the oxygen evolution reaction test, a positive sweep (low voltage to high voltage) was used, with a scan rate of 10 mV / s. During the test, the sample was subjected to continuous and intermittent light and ultrasound, and the changes in current with potential, light, and ultrasound were observed. The test results are shown in the figure. Figure 6 As shown.

[0095] Application Example: The ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst prepared in Example 2 was used as a cathode catalyst in a zinc-air battery. First, 9 mg of photocatalyst, 3 mg of conductive carbon black, and 9 mg of polytetrafluoroethylene powder were measured and dispersed in 1.5 mL of ethanol solution. The solution was ultrasonically treated for 1 hour to make it into a uniform ink-like consistency. Then, the treated solution was uniformly dripped onto a conductive substrate composed of nickel foam and carbon paper composite, with a coating area of ​​3 cm². 2 The loading capacity is 1 mg / cm³ 2 After the catalyst dries, the air cathode portion of the zinc-air battery used in the test is obtained. Simultaneously, a zinc-air battery with an air cathode was prepared using the same method, prepared by mixing commercial oxygen reduction catalyst Pt / C and oxygen evolution catalyst IrO2, denoted as Pt / C-IrO2. Comparisons were made, and the test results are as follows: Figures 8-10 As shown.

[0096] like Figure 1The image shows the XRD pattern of the photocatalyst prepared in Example 2. For the ferroelectric CuInP2S6 nanofiber multifunctional photocatalyst material, the characteristic diffraction peaks of CuInP2S6 appear at 2θ = 13.59°, 29.62°, 34.62°, and 34.74°, which are consistent with the monoclinic Cu... 0.975 The standard card PDF#01-083-0133 (RDB) in (P2S6) is a perfect match.

[0097] like Figure 2 The image shown is an SEM image of the photoelectrocatalyst prepared in Example 2. Figure 2 (a) Before sintering, CuInO2 nanofibers have an interlaced fiber structure and a smooth surface, with a diameter ranging from approximately 200 to 300 nanometers. Figure 2 (b) The morphology of CuInO2 nanofibers after sintering has changed significantly: the originally smooth surface has become rough and exhibits a structure composed of small grains. This change is due to the removal of PVP caused by high-temperature calcination, which forms pores, while the grains constituting the fiber also grow. Figure 2 (c) The diameter of the CuInS2 nanofibers shown did not change significantly, but the small grains that make up the fibers aggregated to form larger grains, and the appearance showed obvious angularity, indicating that a crystal structure may have been formed. Figure 2 (d~e) The CuInP2S6-51060 nanofibers shown are nanosheet-like fibers connected by small nanosheets. Their thickness is much smaller than that of the aforementioned samples, and the fiber diameter is about 100 nm. Figure 2 (f~g) shows CuInP2S6-55060 nanofibers and their magnified SEM images. It can be seen that at 550℃, the thickness of the nanosheets increases and they overlap, while the porosity decreases compared to the former. Figure 2 Images (h-i) show CuInP2S6-55090 nanofibers and their magnified SEM images. After the holding time was extended to 90 minutes, the fiber surface further accumulated and exhibited a certain degree of melting, with the porosity further decreasing. This is due to the further growth of the nanofibers caused by the extended reaction time.

[0098] like Figure 3 The image shown is a TEM image of the photoelectrocatalyst prepared in Example 2. TEM and high-resolution TEM images of CuInP2S6-51060 nanofibers are also shown. Figure 3(a) shows the CuInP2S6-51060 nanofiber structure, which consists of stacked nanosheets connected together, with a diameter of about 100 nm. The high-resolution TEM image shows the lattice fringes of the CuInP2S6-51060 nanofiber, and the lattice spacing is measured to be 0.313 nm, corresponding to the (-114) crystal plane of CuInP2S6, indicating that the sample we synthesized has high crystallinity.

[0099] like Figure 4 The figure shows the XPS spectrum of the photoelectrocatalyst prepared in Example 2. As can be seen from the figure, each element peak is located at its corresponding binding energy, and the valence state of each element corresponds one-to-one with the synthesized substance, while no other impurities are introduced.

[0100] like Figure 5 The image shown is the Nyquist plot of the photoelectrocatalyst prepared in Example 2. From... Figure 5 As can be seen from (a), CuInS2 has the largest Rct, which is 29600Ω. The Rct of CuInP2S6-51060 and CuInP2S6-55090 are 19100Ω and 20700Ω, respectively, while CuInP2S6-55060 has the smallest Rct, which is 2120Ω. Figure 5 (b) shows the Nernst fitting curves of the samples under simulated sunlight irradiation. It can be seen that the impedance of each sample decreases significantly compared to the unirradiated state. Specifically, the Rct of CuInS2 decreases to 15900Ω, while the Rcts of CuInP2S6-51060 and CuInP2S6-55090 decrease to 11200Ω and 12800Ω, respectively. The Rct of CuInP2S6-55060 decreases to 1210Ω. Rct is the charge transfer resistance; a smaller value indicates lower charge transfer resistance. CuInP2S6-55060 has the smallest Rct, yet its photoelectric performance is not the best. This may be because photoelectric performance depends on the efficiency of the entire process of carrier generation, separation, transport, and collection. Good performance in one area is insufficient to improve overall performance. CuInP2S6-51060 achieves the best performance due to its large specific surface area, good ferroelectric properties, and appropriate defect suppression of carrier recombination.

[0101] like Figure 6 The figure shows the LSV curves of the photoelectrocatalyst prepared in Example 2 under various conditions. As can be seen from the figure, the water splitting performance of each sample was improved after the addition of light and ultrasound conditions. The performance improvement was most significant when both light and ultrasound conditions were added simultaneously, and the CuInP2S6 sample exhibited the best performance. Figure 6(a) shows the polarization curves of the CuInP2S6-51060 sample as the cathode under different conditions. Under dark conditions, when the applied potential is in the range of 0 to 0.6 V vs. RHE, the current density of the sample is consistently at the lowest level compared to other conditions. Under simulated sunlight irradiation and dark ultrasound conditions, the current density of the sample is increased compared to the dark condition, reaching 39.7 μA / cm² and 34.4 μA / cm² at 0 V vs. RHE, respectively. Finally, under the illumination plus ultrasound condition, it can be seen that the current density is consistently at its maximum, reaching 42.5 μA / cm² at 0 V vs. RHE, which is 1.43 times the current density under dark conditions. Figure 6 (b) shows the polarization curves of the CuInP2S6-51060 sample as the anode in the potential range of 0.65–1.42 V vs. RHE. As can be seen from the figure, within this potential range, the current density of the sample is significantly increased under illumination, ultrasound, and illumination plus ultrasound conditions compared to the dark state. Particularly at 1.42 V vs. RHE, the sample current density under illumination plus ultrasound conditions reaches 100.7 μA / cm², which is 1.73 times the current density under illumination alone and 2.11 times the current density under dark conditions.

[0102] like Figure 7 The figure shows the current density (it) curves of the photoelectrocatalysts prepared in Example 2 under various conditions. As can be seen from the figure, the current density of CuInP2 increased from 5.13 mA / cm² to 6.59 mA / cm² after illumination, and further increased to 7.29 mA / cm² after ultrasonication; the current density of CuInS2 increased from 4.98 mA / cm² to 6.08 mA / cm² after illumination, and further increased to 6.89 mA / cm² after ultrasonication; and the current density of CuInP2S6 increased from 5.6 mA / cm² to 6.33 mA / cm² after illumination, and further increased to 10.40 mA / cm² after ultrasonication. Notably, CuInP2S6 exhibited the best performance in the oxygen evolution process of electrocatalytic water splitting, and its response to ultrasound was very significant.

[0103] like Figure 8 The figure shows the discharge polarization curve and power density curve of the zinc-air battery when the photoelectrophotocatalyst prepared in Example 2 is used as the air cathode catalyst. As can be seen from the figure, the zinc-air battery using CuInP2S6-51060 nanofibers as the oxygen reduction catalyst has a higher peak power density than the battery assembled using commercially available Pt / C-IrO2.

[0104] like Figure 9The figure shows the specific capacity of a zinc-air battery when the photoelectrocatalyst prepared in Example 2 is used as the air cathode catalyst. It can be seen from the figure that at a discharge current density of 5 mA / cm², the specific capacity of the battery is significantly increased. 2 When using CuInP2S6-51060 catalyst, the specific capacity of zinc-air battery is higher than that of zinc-air battery using Pt / C-IrO2 catalyst. This indicates that using CuInP2S6-51060 catalyst as air cathode catalyst can more effectively improve the specific capacity of zinc-air battery.

[0105] like Figure 10 The figure shows the stepped constant current discharge curves of the zinc-air battery when the photoelectrophotocatalyst prepared in Example 2 is used as the air cathode catalyst. As can be seen from the figure, after the stepped test, the voltages of the two zinc-air batteries coated with CuInP2S6-51060 and Pt / C-IrO2 catalysts, respectively, both recovered to their initial levels at the same current density, indicating that their discharge stability is comparable. Furthermore, the current densities of the batteries are at 10 and 25 mA / cm², respectively. 2 At that time, the zinc-air battery with the cathode coated with CuInP2S6-51060 nanofiber catalyst had a higher voltage than the battery coated with Pt / C-IrO2 catalyst, indicating that the zinc-air battery containing CuInP2S6-51060 nanofiber catalyst has better discharge performance than the zinc-air battery containing Pt / C-IrO2 catalyst.

[0106] In summary, the photoelectrocatalysis provided by this invention has excellent photoelectrocatalytic performance and can be applied to the air cathode portion of a zinc-air battery, thereby improving the various electrochemical performance characteristics of the zinc-air battery.

[0107] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a photoelectrocatalyst, characterized in that, Includes the following steps: S1. Mix water, copper source, indium source and PVP evenly to obtain spinning solution; electrospin the spinning solution and sinter it to obtain intermediate 1. S2. A sulfur source is introduced into intermediate 1 for chemical vapor deposition to obtain intermediate 2; S3. Phosphorus and sulfur sources are introduced into intermediate 2 for chemical vapor deposition to obtain a photoelectrophotocatalyst.

2. The preparation method according to claim 1, characterized in that, In S1, the mass ratio of water, copper source, indium source, and PVP is (5-20):(0.2-0.8):(0.3-0.9):(0.5-3); the parameters of electrospinning include: the flow rate of the spinning solution is 0.2-1 mL / min, the applied positive voltage is 10-30 kV, and the negative voltage is -5--1 kV.

3. The preparation method according to claim 1, characterized in that, In S1, sintering includes heating to 300-800°C at a heating rate of 1-5°C / min and sintering for 1-5 hours; the copper source is selected from one or more of copper acetate, copper nitrate, copper sulfate, and copper chloride; the indium source is selected from one or more of indium acetate, indium nitrate, indium sulfate, and indium chloride.

4. The preparation method according to claim 1, characterized in that, In S2, the sulfur source is selected from one or more of sulfur powder, thioacetamide, thiourea, and ammonium sulfide; the mass ratio of intermediate 1 to sulfur source is (0.002~0.15):(0.01~0.5).

5. The preparation method according to claim 1, characterized in that, In step S2, the process of introducing a sulfur source into intermediate 1 for chemical vapor deposition includes: placing the sulfur source upstream of a dual-temperature-controlled vacuum atmosphere tube furnace and placing intermediate 1 downstream of the same furnace; heating the upstream heating zone to 200–550°C at a heating rate of 1–5°C / min and heating the downstream heating zone to 400–800°C at a heating rate of 5–15°C / min, with a holding time of 1–5 h; and introducing a protective gas during the chemical vapor deposition process, with a flow rate of 20–100 sccm, and the protective gas being selected from one or more of nitrogen and argon.

6. The preparation method according to claim 1, characterized in that, In S3, the mass ratio of intermediate 2, phosphorus source, and sulfur source is (0.002~1.5):(0.01~0.5):(0.01~0.5); the sulfur source is selected from one or more of sulfur powder, thioacetamide, thiourea, and ammonium sulfide; the phosphorus source is selected from one or more of red phosphorus, sodium hypophosphite, white phosphorus, and phosphorus pentasulfide.

7. The preparation method according to claim 1, characterized in that, In step S3, the process of introducing a phosphorus source and a sulfur source into intermediate 2 for chemical vapor deposition includes: placing the phosphorus source and the sulfur source upstream of a dual-temperature-controlled vacuum atmosphere tube furnace, and placing intermediate 2 downstream of the dual-temperature-controlled vacuum atmosphere tube furnace; heating the upstream heating zone to 200-500°C at a heating rate of 5-15°C / min, and heating the downstream heating zone to 300-800°C at a heating rate of 10-25°C / min, with a holding time of 0.5-5 hours; and introducing a protective gas during the chemical vapor deposition process, with a flow rate of 20-100 sccm, and the protective gas being selected from one or more of nitrogen and argon.

8. A photoelectrocatalyst, characterized in that, The photocatalyst is prepared by the preparation method according to any one of claims 1 to 7, wherein the photocatalyst is CuInP2S6 nanofiber material.

9. The application of the photocatalyst according to claim 8 or the photocatalyst prepared by any one of claims 1 to 7 in the photocatalytic splitting of water.

10. The application of the photocatalyst according to claim 8 or the photocatalyst prepared by any one of claims 1 to 7 in a zinc-air battery, characterized in that, The aforementioned photoelectrocatalyst serves as a cathode catalyst in a zinc-air battery.

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