Preparation Of Nickel-cobalt-manganese-based Metal-organic Framework-derived Sulfide Electrocatalyst And Its Overall Water Spiliting Performance

Continued attention to the global energy crisis and environmental issues has prompted people to conduct in-depth research on efficient,environmentally-friendly and sustainable energy systems.Hydrogen energy is considered an ideal substitute for non-renewable energy.The use of electrocatalytic technology to decompose water into hydrogen（H₂）and oxygen（O₂）through hydrogen evolution reaction and oxygen evolution reaction is a promising technology to expand the production of hydrogen energy.Transition metal sulfide catalysts have become a research hotspot due to their rich content,excellent catalytic performance and good electrical conductivity.In the first part of the study,the metal-organic framework MIL-88B（Co/Mn）-NH₂ was loaded on the foamed nickel substrate by hydrothermal method,and after vulcanization,the MILN-based Co₃S₄/MnS₂ with fast electron transfer and dispersed active centers was synthesized.In further research,the nickel in the substrate was leached together with cobalt and manganese to synthesize metal organic framework Ni Co Mn（BDC）x,after being pyrolyzed,a thermal sulfide ion exchange reaction was performed to obtain defect-rich Ni Co MnSx-10 anchored by nitrogen and sulfur co-doped carbon.The results of the study are as follows:（1）Research on the performance of MILN-based Co₃S₄/MnS₂electrocatalytic hydrogen production.The experimental results show that the catalyst has dispersed metal centers and bridged between different sulfide particles by sulfur-doped carbon,which has abundant reaction sites and rapid electron transfer ability.At the same time,a part of the-NH₂ group is retained in the organic ligand,which has a similar strong electron donating ability to that of S^2-,and two different transition metal centers in the material also have similar strong valence ability,which promotes pairwise a double synergy is constructed,which greatly improves the total hydrolysis capacity of the catalyst.The total hydrolysis system constructed by this catalyst achieved a current density of20m A cm^-2 at a low voltage of 1.561 V and ran stably within 80 h.（2）Research on the electrocatalytic performance of Ni Co MnSx-10.The experimental results show that the nitrogen-sulfur co-doped carbon framework enhances the electron transfer ability of the material,and at the same time,due to oxygen vacancies and sulfur defects,it can reduce the ion adsorption barrier and enhance the exposure of edge active sites,making Ni Co MnSx-10 perform well catalytic performance.The total hydrolysis system constructed with it as a catalytic electrode can obtain a current density of 10 m A cm^-2 at a battery voltage of 1.506 V,and can maintain a stable operation for 100 hours at a high current.The performance and stability of the catalyst are better than MILN-based Co₃S₄/MnS₂,and it has stronger industrial application prospects.