Photoelectrode of vulcanized ITO conducting layer and preparation method and application of photoelectrode
A photoelectrode with a sulfurized ITO conductive layer was prepared in one step using a hydrothermal method on an ITO conductive substrate. By combining a conjugated polycarbazole layer and a cocatalyst layer, the complex problem of preparing sulfide photoelectrodes was solved, and efficient and stable photoelectrocatalytic performance was achieved, which is suitable for fields such as photoelectrocatalytic water splitting.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- THE HONG KONG POLYTECHNIC UNIV
- Filing Date
- 2024-10-21
- Publication Date
- 2026-04-21
AI Technical Summary
The existing methods for preparing sulfide photoelectrodes are complex and not conducive to widespread application. Furthermore, traditional methods result in electron/hole pair separation, which is not conducive to interfacial charge transport and makes the catalyst prone to detachment.
A light-absorbing layer was prepared on an ITO conductive substrate using a one-step hydrothermal method. The growth position of the light-absorbing layer compound was controlled by in-situ reaction, and a conjugated polycarbazole layer and a co-catalyst layer were deposited on its surface to form an In2S3/In4SnS8 thin film photoelectrode with a 3D network nanostructure.
The preparation process is simplified, the stability and photoelectrocatalytic performance of the photoelectrode are improved, the reaction contact area between the electrode and the electrolyte is increased, the absorption of sunlight is enhanced, and it has excellent photoelectrocatalytic effect.
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Figure CN121896677A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of optoelectronic materials technology, and in particular relates to a photoelectrode with a sulfurized ITO conductive layer, its preparation method and application. Background Technology
[0002] Hydrogen, as a green and clean secondary energy source, boasts high calorific value, high efficiency, and environmental friendliness, making it widely applicable in numerous fields such as hydrogen fuel cells and hydrogen-powered vehicles to address the current shortage of non-renewable resources. Photoelectrochemical water splitting to produce hydrogen is one of the most promising new energy technologies, primarily utilizing solar energy to catalyze electrode materials in a photoelectrochemical system, thereby splitting water into hydrogen and oxygen. The light absorption, carrier transfer efficiency, and corrosion resistance of the photoanode semiconductor are crucial factors influencing the feasibility and catalytic activity of the entire photoelectrochemical water splitting system.
[0003] In recent years, sulfides have attracted attention due to their superior absorption and catalytic properties; however, their preparation methods are cumbersome and difficult to control for large-scale production. Furthermore, single semiconductors typically exhibit high photo-generated charge recombination rates and low charge separation efficiency. Therefore, to further advance photoelectrocatalysis applications, the preparation of high-efficiency photoelectrodes through easily controllable methods is of significant practical importance.
[0004] As a typical n-type III-VI group chalcogenide semiconductor, In₂S₃ possesses a narrow bandgap of 2.0-2.3 eV and has attracted considerable interest in various applications in recent years. Furthermore, ternary metal sulfide compounds, with their narrow bandgap and relatively negative valence band potential, can serve as visible light-driven photocatalysts. Among these, indium tin sulfide (In₄SnS₈) exhibits a narrow bandgap, strong photocatalytic stability, and excellent optical and electrochemical properties in photocatalysis, energy storage, and optoelectronics. Currently, the preparation of In₄SnS₈ mainly utilizes three chemical substances: stannous chloride dihydrate (SnCl₂·2H₂O), indium chloride tetrahydrate (InCl₃·4H₂O), and sulfur-containing precursors (such as thioacetamide and L-cysteine). The sample morphology is typically a powdered nanostructure, such as nanospheres, nanosheets, or nanosheets. For application in photoelectrocatalysis, photoelectrodes are typically fabricated by attaching catalyst powder to a conductive glass substrate using methods such as spin coating or impregnation. However, these traditional methods result in dense, porous, or aggregated coarse nanoparticles, which are detrimental to electron / hole pair separation and interfacial charge transport. Furthermore, the fabrication process is cumbersome, and the catalyst is prone to detachment. Therefore, providing a simple method for fabricating sulfide heterojunction photoelectrodes is of practical significance. Summary of the Invention
[0005] The purpose of this application is to provide a photoelectrode with a sulfurized ITO conductive layer, its preparation method and application, aiming to solve the problems of complex preparation methods of sulfide photoelectrodes in the prior art, which are not conducive to widespread application.
[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:
[0007] In a first aspect, this application provides a method for preparing a photoelectrode with a sulfurized ITO conductive layer, comprising the following steps:
[0008] Provide ITO conductive substrate,
[0009] A precursor solution containing a sulfur source is provided, and a light-absorbing layer is prepared on the surface of the ITO conductive layer of the ITO conductive substrate by hydrothermal reaction to obtain a photoelectrode of the sulfurized ITO conductive layer.
[0010] In some embodiments, the hydrothermal reaction is carried out at a temperature of 160–220°C for 5–20 hours.
[0011] In some embodiments, the sulfur source includes at least one of thioacetamide, thiourea, and L-cysteine.
[0012] In some embodiments, the concentration of the sulfur source in the sulfur-containing precursor solution is 0.2–1.2 mmol / L.
[0013] In some embodiments, the preparation of the light-absorbing layer further includes: providing a protective gas atmosphere and calcining the light-absorbing layer; wherein the calcination conditions are: raising the reaction temperature to 350-550°C at a heating rate of 2-20°C / min and holding at that temperature for 1-3 hours.
[0014] In some embodiments, the preparation method further includes: preparing a conjugated polycarbazole layer on the surface of the light-absorbing layer opposite to the ITO conductive layer by electrodeposition; and preparing a co-catalyst layer on the surface of the conjugated polycarbazole layer opposite to the light-absorbing layer by electrodeposition.
[0015] In some embodiments, the step of preparing a conjugated polycarbazole layer on the surface of the light-absorbing layer away from the ITO conductive layer by electrodeposition includes: using a standard Ag / AgCl electrode as a reference electrode, a platinum wire as a counter electrode, and an ITO conductive substrate with the light-absorbing layer as a working electrode; providing an electrolyte, and depositing 5 to 20 times at a deposition voltage of -0.8 to 1.4 V; wherein the electrolyte is selected from a mixture of acetonitrile and dichloromethane containing 0.1 mol / L tetrabutylammonium hexafluorophosphate and 4 mmol / L 1,3,5-tris(9-carbazoyl)benzene in a volume ratio of 2:3.
[0016] In some embodiments, the step of preparing a co-catalyst layer on the surface of the conjugated polycarbazole layer away from the light-absorbing layer using an electrodeposition method includes: using a standard Ag / AgCl electrode as a reference electrode, a platinum wire as a counter electrode, and an ITO conductive substrate with the conjugated polycarbazole layer and the light-absorbing layer sequentially disposed from top to bottom as the working electrode; providing a mixed solution of 0.5 mmol / L NiSO4·6H2O and 0.5 mmol / L FeSO4·7H2O as the electrolyte, at -0.8 mA / cm 2 ~-1mA / cm 2 Under the deposition current, deposition lasts for 60s-300s.
[0017] Secondly, this application provides a photoelectrode with a sulfurized ITO conductive layer, the photoelectrode comprising an ITO conductive substrate and a light-absorbing layer disposed sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0018] In some embodiments, the photoelectrode further includes: a conjugated polycarbazole layer disposed on the surface of the light-absorbing layer opposite to the ITO conductive substrate, and a cocatalyst layer disposed on the surface of the conjugated polycarbazole layer opposite to the light-absorbing layer, wherein the conjugated polycarbazole layer uniformly coats the surface of the light-absorbing layer, and the cocatalyst layer is a NiFe-based hydroxyl oxide layer.
[0019] In some embodiments, the thickness of the ITO conductive substrate is 185–1200 nm.
[0020] In some embodiments, the thickness of the light-absorbing layer is 0.5–1 μm.
[0021] In some embodiments, the thickness of the conjugated polycarbazole layer is 5–15 nm.
[0022] In some embodiments, the photoelectrode of the sulfurized ITO conductive layer is used in the field of photoelectric conversion.
[0023] The first aspect of this application provides a method for preparing a photoelectrode with a sulfurized ITO conductive layer. This method only requires a sulfur-containing precursor solution to prepare a light-absorbing layer on an ITO conductive substrate in a one-step hydrothermal process. The growth position of the light-absorbing layer compound can be precisely controlled through in-situ reaction. Simultaneously, the conductive substrate possesses conductivity, allowing for the direct formation of a high-performance photoelectrode. This method not only eliminates the need for spin-coating catalyst powder onto the conductive substrate, but also results in a more stable film that is less prone to detachment during application. The equipment used in this method is simple, the conditions are easy to control, the operation is convenient, the preparation process is green and non-toxic, and the obtained material exhibits uniform growth and good crystallinity, which is beneficial for in-situ growth and large-scale production applications, demonstrating broad industrial development prospects.
[0024] The photoelectrode with the sulfurized ITO conductive layer provided in the second aspect of this application can increase the reaction contact area between the electrode and the electrolyte while improving the absorption of sunlight. The resulting photoelectrode with the sulfurized ITO conductive layer has excellent photoelectrocatalytic effect and shows great application prospects in fields such as photoelectrocatalytic water splitting. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of the fabrication process of the heterojunction photoelectrode provided in the embodiments of this application.
[0027] Figure 2 This is a photocurrent density-voltage (JV) curve of nano-In2S3 / In4SnS8 photoelectrodes prepared with different concentrations of thioacetamide provided in the embodiments of this application.
[0028] Figure 3 This is a JV curve of nano-In2S3 / In4SnS8 photoelectrodes prepared in a 0.4 mmol / L thioacetamide solution for different hydrothermal reaction times, as provided in the embodiments of this application.
[0029] Figure 4 This is a front view of a high-resolution transmission electron microscope image of the heterojunction photoelectrode provided in Embodiment 6 of this application.
[0030] Figure 5 This is a side view of a high-resolution transmission electron microscope image of the heterojunction photoelectrode provided in Embodiment 6 of this application.
[0031] Figure 6 This application contains Embodiment 6 (In2S3 / In4SnS8) and Embodiment 8 (V). S -In2S3 / In4SnS8) and Example 9 (V S JV curve of the In2S3 / In4SnS8-NiFe photoelectrode.
[0032] Figure 7 The area of this application, both in ordinary and logo-containing designs, is 2*2cm. 2 Image of a sample in situ grown on ITO glass using hydrothermal sulfidation method for In2S3 / In4SnS8 heterojunction. Detailed Implementation
[0033] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0034] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0035] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.
[0036] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.
[0037] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.
[0038] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass in the embodiments of this application can be a well-known unit of mass in the chemical industry, such as μg, mg, g, or kg.
[0039] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.
[0040] The first aspect of this application provides a method for preparing a photoelectrode with a sulfurized ITO conductive layer, such as... Figure 1 As shown, it includes the following steps:
[0041] S01. Provides an ITO conductive substrate,
[0042] S02. Provide a precursor solution containing a sulfur source, and prepare a light-absorbing layer on the surface of the ITO conductive layer of the ITO conductive substrate by hydrothermal reaction to obtain a photoelectrode of the sulfurized ITO conductive layer.
[0043] The first aspect of this application provides a method for preparing a photoelectrode with a sulfurized ITO conductive layer. This method only requires a sulfur-containing precursor solution to prepare a light-absorbing layer on an ITO conductive substrate in a one-step hydrothermal process. The growth position of the light-absorbing layer compound can be precisely controlled through in-situ reaction. Simultaneously, the conductive substrate has conductive properties, allowing for the direct formation of a high-performance photoelectrode. This not only eliminates the need for spin-coating catalyst powder onto the conductive substrate, but also results in a more stable film that is less prone to detachment during application. The equipment used in this method is simple, the conditions are easy to control, the operation is convenient, the preparation process is green and non-toxic, and the obtained material grows uniformly with good crystallinity, which is beneficial for in-situ growth and large-scale production applications, and has broad industrial development prospects.
[0044] In step S01, an ITO conductive substrate is provided.
[0045] In some embodiments, the ITO conductive substrate is a substrate containing an ITO conductive layer. The ITO conductive layer is an N-type oxide semiconductor—indium tin oxide—which maintains stable conductivity and visible light transmittance at room temperature and has good chemical stability.
[0046] In some embodiments, the substrate containing the ITO conductive layer includes, but is not limited to, glass substrate, quartz substrate, silicon substrate, and flexible material.
[0047] In some embodiments, the ITO conductive layer in the ITO conductive substrate includes, but is not limited to, single-sided, double-sided, and patterned conductive layer designs.
[0048] In step S02, a precursor solution containing a sulfur source is provided, and a light-absorbing layer is prepared on the surface of the ITO conductive layer of the ITO conductive substrate by hydrothermal reaction to obtain a photoelectrode of the sulfurized ITO conductive layer.
[0049] When applied to photoelectrocatalysis, considering that a larger contact area between the electrode and the electrolyte results in a larger reactive area, a hydrothermal method is used to prepare a 3D nanostructured light-absorbing layer during photoelectrode fabrication. This not only reduces the carrier diffusion distance but also compensates for the short carrier lifetime of bulk materials. Simultaneously, constructing a heterojunction allows for the formation of a space charge region within the material. When the heterojunction layer is very thin, most of the space charge region lies within the light-absorbing layer, thus enabling faster extraction of deep photogenerated carriers to the photoelectrode surface to participate in the reaction.
[0050] In some embodiments, the sulfur source includes at least one of thioacetamide, thiourea, and L-cysteine. In some embodiments, the concentration of sulfur in the precursor solution containing the sulfur source is 0.2–1.2 mmol / L. If the concentration of sulfur in the precursor solution containing the sulfur source is too high or too low, it will affect the sulfur content in the in-situ reaction, affect the structure of the formed light-absorbing layer, and cause the light-absorbing layer to be unable to simultaneously have a network structure and a cubic structure, affecting the reaction contact area between the electrode and the electrolyte, reducing the absorption of sunlight, and weakening its efficiency and stability in photoelectrocatalysis.
[0051] In some specific embodiments, the concentration of sulfur in the sulfur-containing precursor solution includes, but is not limited to, any typical but non-limiting point value or an interval between any two point values, such as 0.2 mmol / L, 0.3 mmol / L, 0.4 mmol / L, 0.5 mmol / L, 0.6 mmol / L, 0.7 mmol / L, 0.8 mmol / L, 0.9 mmol / L, 1.0 mmol / L, 1.1 mmol / L, and 1.2 mmol / L.
[0052] In some specific embodiments, the preparation method of the sulfur-containing precursor solution includes: weighing a certain mass of thioacetamide powder (C2H5NS) and placing it into a certain volume of deionized water, stirring to dissolve and set aside for use.
[0053] Furthermore, a light-absorbing layer is prepared on the surface of the ITO conductive layer of the ITO conductive substrate using a hydrothermal reaction.
[0054] In some embodiments, the conductive substrate needs to be pretreated before the hydrothermal reaction. This pretreatment includes sequentially immersing the conductive substrate in acetone, ethanol, and deionized water, respectively, and then ultrasonically cleaning each for 10 minutes. This is primarily to remove impurities and ensure that no impurities are generated on the surface of the conductive substrate.
[0055] In some embodiments, the hydrothermal reaction temperature is 160–220°C, and the time is 5–20 hours. In some specific embodiments, the hydrothermal reaction temperature includes, but is not limited to, any typical but non-limiting point value or any range between any two point values, such as 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, and 220°C. The reaction time includes, but is not limited to, any typical but non-limiting point value or any range between any two point values, such as 5 hours, 7 hours, 9 hours, 11 hours, 13 hours, 15 hours, 17 hours, and 20 hours.
[0056] In some specific embodiments, an ITO conductive substrate is placed in a stainless steel reactor lined with polytetrafluoroethylene (PTFE), with the surface of the ITO conductive layer facing down. A sulfur-containing precursor solution is then poured into the reactor. The reactor is heated at 160–220°C for 5–20 hours, and the conductive substrate is removed after cooling. The reacted conductive substrate is washed with alcohol and deionized water and then dried for later use. In some specific embodiments, the drying step includes placing the conductive substrate in a vacuum oven for 8–9 hours, maintaining the temperature at 80–85°C.
[0057] This application synthesizes an In2S3 / In4SnS8 light-absorbing layer by sulfiding a conductive substrate using a one-step hydrothermal method. This method is simple, easy to control, and provides a feasible research method for in-situ growth of sulfided nanomaterials. Furthermore, this method can simultaneously and precisely control the growth location of sulfides through in-situ reactions.
[0058] Furthermore, the preparation of the light-absorbing layer also includes: providing a protective gas atmosphere and calcining the light-absorbing layer in a tube furnace; wherein the calcination conditions are: raising the reaction temperature to 350–550°C at a heating rate of 2–20°C / min and holding at that temperature for 1–3 hours. By calcining the In2S3 / In4SnS8 light-absorbing layer in an inert gas atmosphere, it was found that it can reduce the onset voltage and has more defect sites, effectively improving the photoelectrocatalytic performance of the In2S3 / In4SnS8 light-absorbing layer and further increasing the photocurrent density.
[0059] In some embodiments, the protective gas includes, but is not limited to, at least one of nitrogen, hydrogen, and argon.
[0060] In some embodiments, the calcination temperature includes, but is not limited to, any typical but non-limiting point value or a range between any two point values, such as 350°C, 370°C, 400°C, 420°C, 450°C, 470°C, 500°C, and 550°C. The heating rate includes, but is not limited to, any typical but non-limiting point value or a range between any two point values, such as 2°C / min, 5°C / min, 7°C / min, 10°C / min, 12°C / min, 15°C / min, 17°C / min, and 20°C / min. The calcination time includes, but is not limited to, any typical but non-limiting point value or a range between any two point values, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours, and 3 hours.
[0061] In some specific embodiments, the means of enhancing the defects of the light-absorbing layer include, but are not limited to, calcination in a tubular furnace under an inert gas atmosphere, plasma bombardment, etc.
[0062] To further reduce the starting voltage and improve the photoelectrocatalytic performance of the photoelectrode, a conjugated polycarbazole layer and a cocatalyst layer are deposited on the surface of the light-absorbing layer.
[0063] In some embodiments, the preparation method further includes:
[0064] S03. A conjugated polycarbazole layer is prepared on the surface of the light-absorbing layer opposite to the ITO conductive layer by electrodeposition.
[0065] S04. A cocatalyst layer is prepared on the surface of the conjugated polycarbazole layer away from the light-absorbing layer by electrodeposition.
[0066] In step S03, a conjugated polycarbazole layer is prepared on the surface of the light-absorbing layer opposite to the ITO conductive layer using electrodeposition. The conjugated polycarbazole layer is uniformly coated onto the 3D In2S3 / In4SnS8 structure using electrodeposition, and its thickness is controlled. This allows for faster extraction of photogenerated holes from deeper within the In2S3 / In4SnS8 structure to participate in the reaction. Simultaneously, the uniform conjugated polycarbazole layer provides a certain degree of protection, effectively slowing down the photocorrosion of the sulfide electrode.
[0067] In some embodiments, the step of preparing a conjugated polycarbazole layer on the surface of the light-absorbing layer away from the ITO conductive layer by electrodeposition includes: using a standard Ag / AgCl electrode as a reference electrode, a platinum wire as a counter electrode, and an ITO conductive substrate with a light-absorbing layer as a working electrode; providing an electrolyte, and depositing 5 to 20 times at a deposition voltage of -0.8 to 1.4 V; wherein the electrolyte is selected from a mixture of acetonitrile and dichloromethane containing 0.1 mol / L tetrabutylammonium hexafluorophosphate and 4 mmol / L 1,3,5-tris(9-carbazolyl)benzene in a volume ratio of 2:3.
[0068] In step S04, a cocatalyst layer is prepared on the surface of the conjugated polycarbazole layer facing away from the light-absorbing layer using an electrodeposition method. By using electrodeposition to grow the NiFe-based cocatalyst on the In2S3 / In4SnS8-CPF surface and controlling the thickness of the NiFe-based cocatalyst to the nanometer scale, photogenerated carriers from deeper within the In2S3 / In4SnS8 layer can be more quickly extracted to the electrode surface to participate in the reaction.
[0069] In some embodiments, the step of preparing a co-catalyst layer on the surface of the conjugated polycarbazole layer away from the light-absorbing layer using an electrodeposition method includes: using a standard Ag / AgCl electrode as a reference electrode, a platinum wire as a counter electrode, and an ITO conductive substrate with the conjugated polycarbazole layer and the light-absorbing layer sequentially disposed from top to bottom as the working electrode; providing a mixed solution of 0.5 mmol / L NiSO4·6H2O and 0.5 mmol / L FeSO4·7H2O as the electrolyte, at -0.8 mA / cm 2 ~-1mA / cm 2 Under the deposition current, deposition lasts for 60s-300s.
[0070] A second aspect of this application provides a photoelectrode with a sulfurized ITO conductive layer, the photoelectrode comprising an ITO conductive substrate and a light-absorbing layer disposed sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0071] The photoelectrode of the sulfurized ITO conductive layer provided in the second aspect of this application can increase the reaction contact area between the electrode and the electrolyte while improving the absorption of sunlight. The resulting photoelectrode of the sulfurized ITO conductive layer has excellent photoelectrocatalytic effect and shows excellent application prospects in fields such as photoelectrocatalytic water splitting.
[0072] In some embodiments, the ITO conductive substrate is selected from ITO conductive glass, wherein the ITO thin film of the ITO conductive glass is a Sn-doped In₂O₃ thin film, and the crystal structure is consistent with that of In₂O₃. In some embodiments, the thickness of the ITO conductive substrate is 185–1200 nm. In some specific embodiments, the thickness of the ITO conductive substrate includes, but is not limited to, any typical but non-limiting point value or a range between any two point values, such as 185 nm, 260 nm, 650 nm, and 1200 nm.
[0073] Furthermore, a light-absorbing layer was formed on the conductive surface of the conductive substrate. This light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure. The In2S3 / In4SnS8 thin film has both a network structure and a cubic structure, which is beneficial for increasing the reaction contact area between the electrode and the electrolyte while improving the absorption of sunlight.
[0074] In some embodiments, the thickness of the light-absorbing layer is 0.5–1 μm. In some specific embodiments, the thickness of the light-absorbing layer includes, but is not limited to, any typical but non-limiting point value or an interval between any two point values, such as 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, and 1.0 μm.
[0075] Furthermore, a conjugated polycarbazole layer is deposited on the surface of the light-absorbing layer facing away from the conductive substrate, and the conjugated polycarbazole layer is uniformly coated on the surface of the light-absorbing layer; this allows for faster extraction of photogenerated holes from deeper within In2S3 / In4SnS8 to participate in the reaction. Simultaneously, the uniform conjugated polycarbazole layer provides a certain degree of protection, effectively slowing down the photocorrosion of the sulfide electrode.
[0076] In some embodiments, the thickness of the conjugated polycarbazole layer is 5–15 nm. In some specific embodiments, the thickness of the conjugated polycarbazole layer includes, but is not limited to, any typical but non-limiting point value or an interval between any two point values, such as 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, and 15 nm.
[0077] Furthermore, a cocatalyst layer, which is a NiFe-based hydroxyl oxide layer, is disposed on the surface of the conjugated polycarbazole layer facing away from the light-absorbing layer. The NiFe-based cocatalyst is grown on the In2S3 / In4SnS8-CPF surface, and the thickness of the NiFe-based cocatalyst is controlled to be at the nanometer level, which can more quickly guide photogenerated carriers from deeper within In2S3 / In4SnS8 to the electrode surface to participate in the reaction.
[0078] In some embodiments, the photoelectrode with the sulfurized ITO conductive layer is used in the field of photoelectric conversion. Due to the excellent photocatalytic effect of the provided heterojunction photoelectrode, it is mainly used in the field of photoelectric conversion, such as photocatalysis, photoelectric detection, solar cells, integrated circuits, and photodetectors.
[0079] The following description is based on specific embodiments.
[0080] Example 1
[0081] In2S3 / In4SnS8 photoelectrode and its preparation method
[0082] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0083] The preparation method includes the following steps:
[0084] An ITO conductive substrate was provided and ultrasonically cleaned sequentially in acetone, ethanol, and deionized water for 10 min each. A certain mass of thioacetamide powder (C2H5NS) was added to a certain volume of deionized water to prepare a 0.2 mmol / L thioacetamide aqueous solution. The conductive substrate was placed in a stainless steel reactor with a polytetrafluoroethylene liner, conductive side down, and then the thioacetamide aqueous solution was poured into the reactor. The reactor was heated at 200°C for 15 hours, and the conductive substrate was removed after the reactor cooled down. The conductive substrate was cleaned with alcohol and deionized water after the reaction and dried for later use. Under a N2 / H2 atmosphere, the reaction temperature was increased to 500°C at a rate of 10°C / min and held at that temperature for 2 hours for calcination to prepare the light-absorbing layer. The conductive substrate was cleaned with alcohol and deionized water after the reaction and dried in a vacuum oven at 80°C for 8 hours.
[0085] Example 2
[0086] In2S3 / In4SnS8 photoelectrode and its preparation method
[0087] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0088] Compared with Example 1, the preparation method is the same except that "0.2 mmol / L thioacetamide aqueous solution" is replaced with "0.4 mmol / L thioacetamide aqueous solution"; the other steps are the same.
[0089] Example 3
[0090] In2S3 / In4SnS8 photoelectrode and its preparation method
[0091] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0092] Compared with Example 1, the preparation method is the same except that "0.2 mmol / L thioacetamide aqueous solution" is replaced with "0.8 mmol / L thioacetamide aqueous solution"; the other steps are the same.
[0093] Example 4
[0094] In2S3 / In4SnS8 photoelectrode and its preparation method
[0095] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0096] Compared with Example 1, the preparation method is the same except that "a 0.2 mmol / L aqueous solution of thioacetamide" is replaced with "a 1.0 mmol / L aqueous solution of thioacetamide"; the other steps are the same.
[0097] Example 5
[0098] In2S3 / In4SnS8 photoelectrode and its preparation method
[0099] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0100] Compared with Example 2, the preparation method is the same except that "heating the reactor at 200°C for 15 hours" is replaced with "heating the reactor at 200°C for 5 hours"; the other steps are the same.
[0101] Example 6
[0102] In2S3 / In4SnS8 photoelectrode and its preparation method
[0103] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0104] Compared with Example 2, the preparation method is the same except that "heating the reactor at 200°C for 15 hours" is replaced with "heating the reactor at 200°C for 10 hours"; the other steps are the same.
[0105] Example 7
[0106] In2S3 / In4SnS8 photoelectrode and its preparation method
[0107] The provided photoelectrode includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
[0108] Compared with Example 2, the preparation method is the same except that "heating the reactor at 200°C for 15 hours" is replaced with "heating the reactor at 200°C for 20 hours"; the other steps are the same.
[0109] Example 8
[0110] V S -In2S3 / In4SnS8 photoelectrode and its preparation method
[0111] The provided photoelectrode includes a conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein, the light-absorbing layer is a V with a 3D network nanostructure. S -In2S3 / In4SnS8 thin films.
[0112] Compared to Example 6, the preparation method includes a subsequent calcination treatment. After preparing the In2S3 / In4SnS8 film, "the reaction temperature was then raised to 500°C at a heating rate of 10°C / min in a N2 / H2 atmosphere, and held at that temperature for 2 hours for calcination treatment to prepare V..." S -In2S3 / In4SnS8 light-absorbing layer.
[0113] Example 9
[0114] V S -In2S3 / In4SnS8-CPF / NiFe photoelectrode and its preparation method
[0115] The provided photoelectrode comprises, from bottom to top, a conductive substrate, a light-absorbing layer, a conjugated polycarbazole layer, and a cocatalyst layer; wherein the light-absorbing layer is a V with a 3D network nanostructure. S -In2S3 / In4SnS8 thin film, with a conjugated polycarbazole layer (CPF) uniformly coated on the surface of the light-absorbing layer, and the co-catalyst layer is a NiFe-based hydroxyl oxide layer.
[0116] Compared to Example 8, the preparation method involves subsequent electrochemical deposition to prepare the CPF / NiFe layer. The preparation method includes the following steps:
[0117] A standard Ag / AgCl electrode was used as the reference electrode, a platinum wire as the counter electrode, and an ITO glass with an absorbing layer as the working electrode. An electrolyte was provided, consisting of a mixture of acetonitrile and dichloromethane in a volume ratio of 2:3 containing 0.1 mol / L tetrabutylammonium hexafluorophosphate and 4 mmol / L 1,3,5-tris(9-carbazolyl)benzene. A conjugated polycarbazole layer was prepared on the surface of the absorbing layer by deposition 15 times at a deposition voltage of -0.8 to 1.4 V.
[0118] A standard Ag / AgCl electrode was used as the reference electrode, a platinum wire as the counter electrode, and an ITO glass with an absorbing layer coated with a conjugated polycarbazole layer as the working electrode. A mixed solution of 0.5 mmol / L NiSO4·6H2O and 0.5 mmol / L FeSO4·7H2O was provided as the electrolyte, and the electrode was operated at -0.8 mA / cm².2 ~-1mA / cm 2 Under the deposition current, a NiFe-based cocatalyst layer was prepared on the surface of the conjugated polycarbazole layer by deposition for 250 s.
[0119] Performance Testing and Results Analysis
[0120] (I) The performance of the photoelectrodes obtained in Examples 1 to 4 (the concentrations of the thioacetamide aqueous solution differed in the four examples) was analyzed. The specific testing method was a standard three-electrode photoelectrochemical test (using the photoelectrode as the working electrode, the standard Ag / AgCl electrode as the reference electrode, and a platinum wire as the counter electrode; the electrolyte was a 0.35M / 0.25M Na₂SO₃ / Na₂S solution). The results are as follows: Figure 2 As shown, Example 2 (a 0.4 mmol / L aqueous solution of thioacetamide) exhibits the best photoelectric properties.
[0121] Analysis of Examples 2, 5-7 (the above four examples use 0.4 mmol / L thioacetamide aqueous solution, and the reaction time differs), such as Figure 3 As shown, the heterojunction photoelectrode obtained in Example 6 (reaction time 10 hours, using a 0.4 mmol / L aqueous solution of thioacetamide) exhibits the best photoelectric performance, with a photocurrent density reaching 1.85 mA cm⁻¹ at 1.23 V vs. RHE. -2 .
[0122] (II) The heterojunction photoelectrode provided in Example 6 was analyzed by high-resolution transmission electron microscopy. The front view is shown below. Figure 4 Side view as shown Figure 5 .
[0123] (three) Figure 6 Examples 6 (In2S3 / In4SnS8) and 8 (V) are shown. S -In2S3 / In4SnS8) and Example 9 (V S JV curve of the In2S3 / In4SnS8-NiFe photoelectrode. Figure 6 It can be seen that after depositing the conjugated polycarbazole layer and the NiFe-based cocatalyst, the catalytic performance of the nano-In2S3 / In4SnS8 photoelectrode obtained in Example 9 was further improved, reaching 14 mA cm⁻¹ at 1.23 V vs. RHE. -2 .
[0124] (Four) Figure 7 The area shown is 2*2cm in both plain and logo designs. 2Images of samples of In2S3 / In4SnS8-based heterojunctions grown in situ on ITO glass via hydrothermal sulfidation are shown. It can be seen that In2S3 / In4SnS8-based heterojunctions can be grown in situ in both cases, and the resulting materials are uniformly grown and have good crystallinity.
[0125] In summary, this application provides a method for preparing a photoelectrode with a sulfurized ITO conductive layer. This method only requires a sulfur-containing precursor solution to prepare a light-absorbing layer on an ITO conductive substrate in a one-step hydrothermal process. The growth position of the light-absorbing layer compound can be precisely controlled through in-situ reaction. Simultaneously, the conductive substrate possesses conductivity, allowing for the direct formation of a high-performance photoelectrode. This method not only eliminates the need for spin-coating catalyst powder onto the conductive substrate, but also results in a more stable film that is less prone to detachment during application. The equipment used in this method is simple, the conditions are easy to control, the operation is convenient, the preparation process is green and non-toxic, and the obtained material exhibits uniform growth and good crystallinity, which is beneficial for in-situ growth and large-scale production applications, demonstrating broad industrial development prospects.
[0126] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for preparing a photoelectrode with a sulfurized ITO conductive layer, characterized in that, Includes the following steps: Provide ITO conductive substrate, A precursor solution containing a sulfur source is provided, and a light-absorbing layer is prepared on the surface of the ITO conductive layer of the ITO conductive substrate by hydrothermal reaction to obtain a photoelectrode of the sulfurized ITO conductive layer.
2. The method for preparing a photoelectrode with a sulfurized ITO conductive layer according to claim 1, characterized in that, The hydrothermal reaction is carried out at a temperature of 160–220°C for 5–20 hours.
3. The method for preparing a photoelectrode with a sulfurized ITO conductive layer according to claim 1, characterized in that, The sulfur source includes at least one of thioacetamide, thiourea, and L-cysteine; and / or, In the precursor solution containing the sulfur source, the concentration of the sulfur source is 0.2–1.2 mmol / L.
4. The method for preparing a photoelectrode with a sulfurized ITO conductive layer according to claim 1, characterized in that, The preparation of the light-absorbing layer further includes: providing a protective gas atmosphere and calcining the light-absorbing layer; wherein the calcination conditions are: raising the reaction temperature to 350-550°C at a heating rate of 2-20°C / min and holding at that temperature for 1-3 hours.
5. The method for preparing a photoelectrode with a sulfurized ITO conductive layer according to claim 1, characterized in that, The preparation method further includes: preparing a conjugated polycarbazole layer on the surface of the light-absorbing layer opposite to the ITO conductive layer by electrodeposition; and preparing a co-catalyst layer on the surface of the conjugated polycarbazole layer opposite to the light-absorbing layer by electrodeposition.
6. The method for preparing a photoelectrode with a sulfurized ITO conductive layer according to claim 5, characterized in that, The step of preparing a conjugated polycarbazole layer on the surface of the light-absorbing layer opposite to the ITO conductive layer using electrodeposition includes: using a standard Ag / AgCl electrode as a reference electrode, a platinum wire as a counter electrode, and an ITO conductive substrate with the light-absorbing layer as the working electrode; providing an electrolyte, and depositing 5 to 20 times at a deposition voltage of -0.8 to 1.4 V; wherein the electrolyte is selected from a mixture of acetonitrile and dichloromethane containing 0.1 mol / L tetrabutylammonium hexafluorophosphate and 4 mmol / L 1,3,5-tris(9-carbazolyl)benzene in a volume ratio of 2:3; and / or, The step of preparing a cocatalyst layer on the surface of the conjugated polycarbazole layer away from the light-absorbing layer using an electrodeposition method includes: using a standard Ag / AgCl electrode as a reference electrode, a platinum wire as a counter electrode, and an ITO conductive substrate with the conjugated polycarbazole layer and the light-absorbing layer sequentially disposed from top to bottom as the working electrode; providing a mixed solution of 0.5 mmol / L NiSO4·6H2O and 0.5 mmol / L FeSO4·7H2O as the electrolyte, at -0.8 mA / cm 2 ~-1mA / cm 2 Under the deposition current, deposition lasts for 60s-300s.
7. A photoelectrode with a sulfurized ITO conductive layer, characterized in that, The photoelectrode of the sulfurized ITO conductive layer includes an ITO conductive substrate and a light-absorbing layer arranged sequentially from bottom to top; wherein, the light-absorbing layer is an In2S3 / In4SnS8 thin film with a 3D network nanostructure.
8. The photoelectrode with a sulfurized ITO conductive layer according to claim 7, characterized in that, The photoelectrode further includes: a conjugated polycarbazole layer disposed on the surface of the light-absorbing layer opposite to the ITO conductive substrate, and a cocatalyst layer disposed on the surface of the conjugated polycarbazole layer opposite to the light-absorbing layer, wherein the conjugated polycarbazole layer is uniformly coated on the surface of the light-absorbing layer, and the cocatalyst layer is a NiFe-based hydroxyl oxide layer.
9. The photoelectrode with a sulfurized ITO conductive layer according to claim 8, characterized in that, The thickness of the ITO conductive substrate is 185–1200 nm; and / or, The thickness of the light-absorbing layer is 0.5–1 μm; and / or, The thickness of the conjugated polycarbazole layer is 5–15 nm.
10. The photoelectrode with a sulfurized ITO conductive layer according to any one of claims 7 to 9, characterized in that, The photoelectrode of the sulfurized ITO conductive layer is used in the field of photoelectric conversion.