A self-supporting electrocatalytic electrode, a preparation method thereof and application thereof in hydrogen evolution from electrolysis of bunsen reaction products
Patent Information
- Application Number
- CN202311286334.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-07
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2043-10-07
AI Technical Summary
然而，蒸汽甲烷重整和煤气化制备氢气仍会排放大量的CO2温室气体，通过电解水制氢是研究者们更倾向的理想制氢方式，但是由于电解水过程中阳极析氧反应较大的过电位使得电解水制氢的实际应用受到了限制
[0013]本发明使用循环伏安法进行电沉积制备以碳布为基底表面沉积锌硫化合物和氮掺杂碳（ZnSx/NC@CC）复合材料的自支撑电催化电极，电沉积方法可以通过简单的控制外加电位来控制沉积过程，易于制备纳米材料，且设备简便、易于操作、沉积速度快、制样时间短。相较于常用电催化电极铂，过渡金属硫化物含量丰富且制备成本较低，同时具有较高的电导率和优越的电化学性能。掺杂杂原子制备的缺陷碳基材料具有优异的电催化性能，锌硫化合物与氮掺杂碳纳米材料负载在碳布上有利于进一步的提高它们的电化学活性和导电性。
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Figure CN117344341B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nanotechnology, specifically relating to a method for depositing zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. x / NC@CC) composite self-supporting electrocatalytic electrode, preparation method and its application in hydrogen evolution of Bunsen reaction products. Background Technology
[0002] Driven by the demands of human societal development and the increasingly severe environmental pollution, energy development and production issues urgently need to be addressed. Currently, the increasing use of fossil fuels results in the emission of large amounts of greenhouse gases into the atmosphere, not only exacerbating the depletion of limited fossil fuel resources but also severely eroding the environment and impacting the health and safety of organisms. Hydrogen, a lightest, colorless, odorless, and non-toxic gas, is a new type of clean energy source. When used, hydrogen emits almost nothing except water, effectively avoiding the emission of carbon dioxide and air pollutants. The three main industrial hydrogen production methods are steam methane reforming, coal gasification, and water electrolysis. However, steam methane reforming and coal gasification still emit large amounts of CO2 greenhouse gases. Water electrolysis is the preferred method for hydrogen production, but the large overpotential of the oxygen evolution reaction at the anode during water electrolysis limits its practical application.
[0003] Hydrogen production via the sulfur-iodine (SI) cycle holds promise as an effective route for large-scale hydrogen production. This process involves three reactions: the Bunsen reaction, sulfuric acid decomposition, and hydroiodic acid decomposition, with the reaction products recyclable. Hydrogen can be efficiently produced by directly electrolyzing the Bunsen reaction products, hydroiodic acid and sulfuric acid. Compared to the theoretical decomposition voltage of water (1.23 V), the theoretical decomposition voltage of hydroiodic acid is only 0.53 V. Therefore, the search for low-cost, high-performance electrocatalysts has become a new research direction.
[0004] Carbon cloth substrates, composed of carbon fibers, offer excellent conductivity, flexibility, corrosion resistance, and relatively low cost. Compared to platinum, a commonly used electrocatalytic electrode, transition metal sulfides are abundant and have lower preparation costs, while also exhibiting high conductivity and superior electrochemical performance. Defect-based materials prepared by doping heteroatoms possess excellent electrocatalytic performance, and loading zinc-sulfur compounds and nitrogen-doped carbon nanomaterials onto carbon cloth further enhances their electrochemical activity and conductivity. Summary of the Invention
[0005] The purpose of this invention is to provide a method for depositing zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. xThis invention relates to a self-supporting electrocatalytic electrode made of (NC@CC) composite material, its preparation method, and its application in hydrogen evolution of Bunsen reaction products. The invention employs in-situ synthesis via static deposition and electrodeposition methods, successfully loading zinc-sulfur compounds and nitrogen-doped carbon (ZnS) onto carbon cloth. x The self-supporting electrocatalytic electrode prepared from the (NC@CC) composite material exhibits low electrochemical impedance and excellent electron transport performance.
[0006] The present invention describes a method for depositing zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. x The preparation method of the / NC@CC composite self-supporting electrocatalytic electrode is as follows:
[0007] (1) Surface treatment of carbon cloth
[0008] A mixed acid solution was prepared by mixing sulfuric acid solution with a mass concentration of 8-15% and nitric acid solution with a mass concentration of 8-15% at a volume ratio of 1:3. The cut carbon cloth (1×2 cm) was placed in the mixed acid solution and ultrasonically treated for 5-10 minutes, and then soaked for 30-40 hours. After being removed, it was rinsed several times with distilled water and anhydrous ethanol (mass fraction ≥99.7%), and dried at 50-70 °C to obtain the pretreated carbon cloth.
[0009] (2) Precursors of zinc-sulfur compounds and nitrogen-doped carbon composite materials were statically deposited on the surface of carbon cloth.
[0010] 0.30 g of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 1.50 g of 2-methylimidazole (C4H6N2) were dissolved in 30-50 mL of deionized water to form a homogeneous solution. The 2-methylimidazole solution was poured into the zinc nitrate solution, and then the carbon cloth obtained in step (1) was placed in it. After standing for 3-5 h, the carbon cloth was removed and dried at 50-70 °C, so that the precursor of zinc sulfur compound and nitrogen-doped carbon composite material was deposited on the surface of the carbon cloth.
[0011] (3) Electrodeposition of zinc-sulfur compounds and nitrogen-doped carbon composite precursors on the surface of carbon cloth
[0012] 3.80 g of thiourea (CH4N2S) was dissolved in 30-50 mL of deionized water to form a homogeneous solution. This solution was used as the electrolyte solution in a three-electrode electrolytic cell system. A platinum electrode was used as the counter electrode, a saturated calomel electrode as the reference electrode, and carbon cloth with surface-deposited zinc-sulfur compounds and nitrogen-doped carbide precursors prepared in step (2) was used as the working electrode. Electrodeposition was performed using cyclic voltammetry. The deposition voltage range was -1.8 V to 0.2 V, the scan rate was 1-5 mV / s, and the number of cycles was 3-15. After electrodeposition, the surface of the carbon cloth was washed several times with deionized water and finally dried at 50-70 °C to obtain a carbon cloth substrate with surface-deposited zinc-sulfur compounds and nitrogen-doped carbon (ZnS). x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0013] This invention uses cyclic voltammetry to prepare zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the surface of a carbon cloth substrate by electrodeposition. x Self-supporting electrocatalytic electrodes made of (NC@CC) composite materials are used. The electrodeposition method allows for easy control of the deposition process by adjusting the applied potential, facilitating the preparation of nanomaterials. The equipment is simple, easy to operate, and offers fast deposition speeds and short sample preparation times. Compared to commonly used platinum electrocatalytic electrodes, transition metal sulfides are abundant and have lower preparation costs, while also exhibiting high conductivity and superior electrochemical performance. Defective carbon-based materials prepared by doping heteroatoms possess excellent electrocatalytic performance. Loading zinc-sulfur compounds and nitrogen-doped carbon nanomaterials onto carbon cloth further enhances their electrochemical activity and conductivity.
[0014] This invention uses carbon cloth as a substrate and prepares zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the surface of the carbon cloth substrate by cyclic voltammetry electrodeposition. x The self-supporting electrocatalytic electrode of the / NC@CC composite material features a nanostructure that facilitates ion diffusion, electron transport, and the effective utilization of the activity of zinc-sulfur compounds and nitrogen-doped carbides, reducing the electrode's internal resistance and resulting in excellent electrochemical performance. For example, with a sample subjected to 9 cyclic voltammetry electrodeposition cycles at a scan rate of 3 mV / s, a current density of 100 mA / cm² can be achieved with a potential of only 0.26 V. 2 After 2000 cycles of cyclic voltammetry testing, the material still maintained 97.82% of the initial current density, demonstrating its good electrocatalytic stability. Attached Figure Description
[0015] This invention employs a FEI XL30ESEM-FEG (FEI GmbH, Netherlands) field emission scanning electron microscope (FESEM) to observe the crystal morphology of the product, and an ESCALAB 250 (Thermal Instruments, USA) X-ray photoelectron spectrometer to perform electron spectroscopy. Electrochemical performance testing was conducted using a CS120H electrochemical workstation (Wuhan KOST Instruments Co., Ltd.). Its morphology, composition, and other properties are characterized as follows:
[0016] Figure 1 These are examples 1-5 (corresponding to curves 1-5), which are preparations using carbon cloth as a substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the surface. x Linear scanning voltammetry (SSV) curves of the self-supporting electrocatalytic electrode of the / NC@CC composite material are shown. Curve 1 is the SSV curve of acid-treated carbon cloth. Curves 2, 3, and 4 are the curves of zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the carbon cloth substrate after electrodeposition using cyclic voltammetry. The number of cyclic voltammetry cycles was the same, 9 cycles, and the cyclic voltammetry scan rates were 1 mV / s, 3 mV / s, and 5 mV / s, respectively. x Linear scan voltammetry curves of the self-supporting electrocatalytic electrode of the / NC@CC composite material. Curve 5 is the linear scan voltammetry curve of the precursor deposited on carbon cloth before the electrodeposition sulfidation method.
[0017] Figure 2 The zinc-sulfur compounds and nitrogen-doped carbon (ZnS) were deposited on the surface of a carbon cloth substrate using cyclic voltammetry with different numbers of electrodeposition cycles at a scan rate of 3 mV / s, as prepared in Examples 3 (curve 3) and 6-9 (corresponding to curves 6-9 respectively). x Linear scanning voltammetry curves of the self-supporting electrocatalytic electrode of the / NC@CC composite material. Curve 3 has 9 cyclic voltammetry electrodeposition cycles, while curves 6, 7, 8, and 9 have 3, 6, 12, and 15 cyclic voltammetry electrodeposition cycles, respectively.
[0018] Figure 3 The carbon cloth prepared in Example 3 has zinc-sulfur compounds and nitrogen-doped carbides (ZnS) deposited on its surface. x FESEM image of the / NC@CC composite material.
[0019] Figure 4 This is an example of a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x XPS spectra of a self-supporting electrocatalytic electrode of the ( / NC@CC) composite material. Figure 4 (a) is the XPS spectrum of C 1s, (b) is the XPS spectrum of N 1s, (c) is the XPS spectrum of Zn 2p, and (d) is the XPS spectrum of S 2p.
[0020] Figure 5 The acid-treated carbon cloth prepared in Examples 1 (curve 1) and 3 (curve 3) and the carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the surface are examples 2 and 3. x Nyquist plot of the self-supporting electrocatalytic electrode of the / NC@CC composite material.
[0021] Figure 6 This is an example of a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x Linear sweep voltammetry curves of the first cycle (curve 3) and the 2000th cycle (curve 10) of the self-supporting electrocatalytic electrode of the / NC@CC composite material.
[0022] Figure 7 This is an example of a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x A comparison curve of theoretical and experimental hydrogen production for the self-supporting electrocatalytic electrode of the / NC@CC composite material.
[0023] like Figure 1 The image shows an electrochemical test performed using a three-electrode system. The working electrode is a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x The self-supporting electrocatalytic electrode of the / NC@CC composite material has a platinum electrode of the same area as the counter electrode and a saturated calomel electrode as the reference electrode. The comparison curves show that as the electrodeposition scan rate increases, the current density first increases (reaching a maximum value of 3 mV / s) and then decreases. Moreover, the current density of all carbon cloths with zinc-sulfur compounds and nitrogen-doped carbides deposited on the surface is higher than that of the acid-treated carbon cloth (Example 1).
[0024] like Figure 2 The image shows an electrochemical test performed using a three-electrode system. The working electrode is a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x A self-supporting electrocatalytic electrode of the / NC@CC composite material was used, with a platinum electrode of the same area as the counter electrode and a saturated calomel electrode as the reference electrode. Comparison of the curves revealed that the current density was highest at 9 cyclic voltammetry cycles, and decreased with increasing cyclic voltammetry cycles, proving that 9 cyclic voltammetry cycles were the optimal number.
[0025] like Figure 3 As shown, the zinc-sulfur compounds and nitrogen-doped carbides deposited on the surface of the carbon cloth are uniformly attached to the carbon cloth in the form of a thin film.
[0026] like Figure 4 As shown, Figure 4(a) is the XPS spectrum of C 1s, with the diffraction peaks at binding energies of 284.8 eV and 285.43 eV corresponding to CC and CN, respectively; Figure 4 (b) is the XPS spectrum of N 1s, and the diffraction peak with a binding energy of 400.62 eV indicates the presence of graphitic nitrogen; Figure 4 (c) is the XPS spectrum of Zn 2p, with diffraction peaks at binding energies of 1022.68 eV and 1045.68 eV corresponding to Zn 2p, respectively. 3 / 2 and Zn 2p 1 / 2 ; Figure 4 (d) shows the XPS spectrum of S 2p, with diffraction peaks at binding energies of 164.09 eV and 165.46 eV corresponding to S 2p, respectively. 3 / 2 and S 2p 1 / 2 The remaining diffraction peaks represent the presence of SO. The XPS energy dispersive spectroscopy indicates that zinc-sulfur compounds and nitrogen were successfully doped into the carbon structure.
[0027] like Figure 5 As shown, the smaller the radius of the semicircle of the curve, the lower the impedance. This figure indicates that the self-supporting electrocatalytic electrode with zinc-sulfur compound and nitrogen-doped carbon composite material deposited on the carbon cloth surface prepared in the experiment has low impedance.
[0028] like Figure 6 As shown, after 2000 cycles of cyclic voltammetry testing, the material can still maintain 97.82% of the initial current density at 1.0 V, proving that the material has good electrocatalytic stability.
[0029] like Figure 7 As shown, the working electrode (anode) is a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x A self-supporting electrocatalytic electrode of the (NC@CC) composite material was prepared, with a platinum electrode of the same area as the cathode. The two electrodes were placed in a sealed two-chamber electrolytic cell, one with a 1 mol / L hydroiodic acid and 0.5 mol / L sulfuric acid mixture as the electrolyte, and the other with a 2 mol / L sulfuric acid solution. A hydrogen collection device was connected to the cathode side for electrochemical testing, recording the current and actual hydrogen production. The theoretical hydrogen production was calculated using Faraday's law. The figure shows that the theoretical and actual hydrogen production are basically consistent, indicating that the Faraday efficiency of the self-supporting electrocatalytic electrode of the carbon cloth surface-deposited zinc-sulfur compound and nitrogen-doped carbon composite material prepared in this invention is close to 100%.
[0030] Faraday efficiency calculation method:
[0031]
[0032]
[0033] Where N T N is the theoretical number of moles of hydrogen produced. E η is the number of moles of hydrogen collected by actual electrolysis, Q is the total charge in the electrolysis process, F is the Faraday constant, n is the number of electrons gained or lost in the electrochemical reaction, and η is the Faraday efficiency. Detailed Implementation
[0034] The present invention will be described below through specific embodiments, but is not limited thereto. Unless otherwise specified, all solutions referred to in the present invention are aqueous solutions.
[0035] Example 1:
[0036] A mixed acid solution was prepared by mixing a 10% sulfuric acid solution and a 10% nitric acid solution at a volume ratio of 1:3. The cut carbon cloth (1×2 cm) was placed in the mixed acid solution and ultrasonically treated for 8 minutes, and then soaked for 35 hours. After being taken out, it was rinsed several times with distilled water and anhydrous ethanol (mass fraction ≥99.7%), and dried at 60 °C to obtain the pretreated carbon cloth.
[0037] Example 2:
[0038] (1) Surface treatment of carbon cloth
[0039] A mixed acid solution was prepared by mixing a 10% sulfuric acid solution and a 10% nitric acid solution at a volume ratio of 1:3. The cut carbon cloth (1×2 cm) was placed in the mixed acid solution and ultrasonically treated for 8 minutes, and then soaked for 35 hours. After being taken out, it was rinsed several times with distilled water and anhydrous ethanol (mass fraction ≥99.7%), and dried at 60 °C to obtain the pretreated carbon cloth.
[0040] (2) Precursors of zinc-sulfur compounds and nitrogen-doped carbon composite materials were statically deposited on the surface of carbon cloth.
[0041] 0.30 g of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 1.50 g of 2-methylimidazole (C4H6N2) were dissolved in 40 mL of deionized water to form a homogeneous solution. The 2-methylimidazole solution was poured into the zinc nitrate solution and a piece of carbon cloth obtained in step (1) was placed in it. After standing for 4 h, the carbon cloth was taken out and dried at 60 °C to obtain the precursor of zinc sulfur compound and nitrogen-doped carbon composite material deposited on the surface of the carbon cloth.
[0042] (3) Electrodeposition of zinc-sulfur compounds and nitrogen-doped carbon composite precursors on the surface of carbon cloth
[0043] 3.80 g of thiourea (CH4N2S) was dissolved in 40 mL of deionized water to form a homogeneous solution. This solution was used as the electrolyte in a three-electrode electrolytic cell system, with a platinum electrode as the counter electrode, a saturated calomel electrode as the reference electrode, and a carbon cloth containing a zinc-sulfur compound and nitrogen-doped carbide precursor deposited on its surface as the working electrode. Electrodeposition was performed using cyclic voltammetry. The deposition voltage range was -1.8 V to 0.2 V, the scan rate was 1 mV / s, and the number of cycles was 9. After electrodeposition, the sample was washed several times with deionized water and dried at 60 °C to obtain a carbon cloth substrate with a surface deposit of zinc-sulfur compound and nitrogen-doped carbon (ZnS). x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0044] Example 3:
[0045] As in Example 2, the cyclic voltammetric electrodeposition scan rate was adjusted to 3 mV / s to obtain zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the surface of a carbon cloth substrate. x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0046] Example 4:
[0047] As in Example 2, the cyclic voltammetric electrodeposition scan rate was adjusted to 5 mV / s to obtain zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on the surface of a carbon cloth substrate. x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0048] Example 5:
[0049] (1) Surface treatment of carbon cloth
[0050] A mixed acid solution was prepared by mixing a 10% sulfuric acid solution and a 10% nitric acid solution at a volume ratio of 1:3. The cut carbon cloth (1×2 cm) was placed in the mixed acid solution and ultrasonically treated for 8 minutes, and then soaked for 35 hours. After being taken out, it was rinsed several times with distilled water and anhydrous ethanol (mass fraction ≥99.7%), and dried at 60 °C to obtain the pretreated carbon cloth.
[0051] (2) Precursors of zinc-sulfur compounds and nitrogen-doped carbon composite materials were statically deposited on the surface of carbon cloth.
[0052] 0.30 g of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 1.50 g of 2-methylimidazole (C4H6N2) were dissolved in 40 mL of deionized water to form homogeneous solutions. The 2-methylimidazole solution was then poured into the zinc nitrate solution, and a piece of pre-treated carbon cloth was placed on top. After standing deposition for 4 h, the carbon cloth was removed and dried at 60 °C, yielding a carbon cloth substrate with zinc-sulfur compounds and nitrogen-doped carbon (ZnS) deposited on its surface. x / NC@CC) composite material precursor self-supporting electrocatalytic electrode.
[0053] Example 6:
[0054] As in Example 3, the number of cycles of cyclic voltammetry electrodeposition was adjusted to 3 cycles, resulting in the deposition of zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0055] Example 7:
[0056] As in Example 3, the number of cycles of cyclic voltammetry electrodeposition was adjusted to 6 cycles, resulting in the deposition of zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0057] Example 8:
[0058] As in Example 3, the number of cycles of cyclic voltammetry electrodeposition was adjusted to 12 cycles, resulting in the deposition of zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
[0059] Example 9:
[0060] As in Example 3, the number of cycles of cyclic voltammetry electrodeposition was adjusted to 15 cycles, resulting in the deposition of zinc-sulfur compounds and nitrogen-doped carbon (ZnS) on a carbon cloth substrate. x Self-supporting electrocatalytic electrode of (NC@CC) composite material.
Claims
1. A method for preparing a self-supporting electrocatalytic electrode based on carbon cloth, comprising the following steps: (1) Surface treatment of carbon cloth A mixed acid solution was prepared by mixing sulfuric acid solution with a mass concentration of 8-15% and nitric acid solution with a mass concentration of 8-15% at a volume ratio of 1:
3. The carbon cloth was placed in the mixed acid solution and ultrasonically treated for 5-10 minutes, and then soaked for 30-40 hours. After being taken out, it was rinsed several times with distilled water and anhydrous ethanol, and dried at 50-70 °C to obtain the pretreated carbon cloth. (2) Precursor deposition on carbon cloth surface 0.30 g of zinc nitrate hexahydrate and 1.50 g of 2-methylimidazole were dissolved in 30-50 mL of deionized water to form a homogeneous solution. The 2-methylimidazole solution was poured into the zinc nitrate solution, and then the carbon cloth obtained in step (1) was placed in it. After standing for 3-5 h, the carbon cloth was removed and dried at 50-70 °C to deposit the precursor on the surface of the carbon cloth. (3) Sulfurization of carbon cloth surface precursor by electrodeposition 3.80 g of thiourea was dissolved in 30-50 mL of deionized water to form a homogeneous solution. This solution was used as an electrolyte solution in a three-electrode electrolytic cell system. A platinum electrode was used as the counter electrode and a saturated calomel electrode was used as the reference electrode. The carbon cloth of the surface deposition precursor prepared in step (2) was used as the working electrode. Electrodeposition was performed by cyclic voltammetry. After the electrodeposition was completed, the surface of the carbon cloth was washed several times with deionized water and finally dried at 50-70 °C to obtain a self-supporting electrocatalytic electrode based on carbon cloth. In step (3), the deposition voltage range of the cyclic voltammetry is -1.8 V to 0.2 V, the scan rate is 3 to 5 mV / s, and the number of cycles is 9 to 15.
2. A self-supporting electrocatalytic electrode based on carbon cloth, characterized in that: It is prepared by the method described in claim 1.
3. The application of the self-supporting electrocatalytic electrode based on carbon cloth as described in claim 2 in the hydrogen evolution of the products of the Bunsen reaction.