Synthesis Of Sulfur(Phosphorus) Compound Based On Dual Transition-metal Electrocatalysts And Their Electricatalytic Performance For Hydrogen Evolution Reaction

In order to solve the increasingly severe energy crisis and environmental pollution problems,the development of efficient,environmental friendly and renewable new energy has become an important research topic in the energy field all over the world.Hydrogen is an ideal alternative to traditional fossil fuels because of its advantages of high energy density,pollution-free combustion and renewability.Electrolytic water hydrogen evolution reaction(HER)is one of the main ways to produce high-purity hydrogen.Reasonable design of HER catalyst with high efficiency,low cost and environmental friendship is an effective strategy to reduce the cost of hydrogen generation and improve the efficiency of the conversion from electric energy to hydrogen energy.Among the HER catalysts,transition metal sulfides and phosphates have attracted extensive attention due to their high earth abundance and high catalytic activity.In this thesis,Cu3BiS3 and NiCoP were respectively synthesized in situ on Cu and Ni foam as the HER catalysts by a simple hydrothermal method.The micro-morphology,ingredients and phase structure of Cu3BiS3 and NiCoP were characterized and their electrocatalytic HER performance in electrocatalytic hydrogen evolution was tested.The details are as follows:(1)Cu3BiS3/CF was prepared with a substrate of copper foam(CF)by one-step hydrothermal method.The flower-like structures formed on the CF are composed of Cu3BiS3 nanosheets.The large specific surface area and hyperbranched structures facilitate the contact between electrolyte and the active site as well as the release of gas products during HER.The results of electrochemical performance tests show that the Cu3BiS3/CF catalyst has excellent performance with a low overpotential of 273 mV at the current density of 10 mA cm-2 and a small Tafel slope of 143.7 mV dec-1 in an alkaline solution,which indicated that the catalyst has good catalytic activity.In addition,after 500 CV cycles or working for 30 h at 100 mA cm-2 by chronopotentiometry,the potential did not decrease significantly,indicating that the Cu3BiS3/CF has high stability.(2)NiCoP/NF catalyst was prepared by hydrothermal method and chemical vapor deposition phosphating on nickel foam substrate.The dandelion-like NiCoP grown on the surface of nickel foam(NF)increased the specific surface area of the catalyst and exposed more active sites,which enhances the catalytic activity of the catalyst.The electrochemical performance test results showed that the NiCoP/NF catalyst has a small onset-potential of 85 mV,Tafel slope of 113.3 mV dec-1,and a large specific surface area,which shows an excellent catalytic performance in alkaline electrolyte.In addition,the stability test indicated that the catalyst has significant long-term stability.