Preparation Of Transition Metal Sulfur And Phosphide And Study On The Properties Of HER And OER

The development of sustainable and pollution-free energy sources to replace the currently dominant but increasingly“depleted”fossil fuels remains a major challenge.The energy conversion between electricity and chemical energy is a promising“bridge”to alleviate energy shortages through synergies with sustainable energy sources such as wind and solar.Electrocatalytic water splitting to produce clean hydrogen（H₂）and oxygen（O₂）is a viable alternative to other energy storage technologies such as lithium ion batteries or fuel cells.However,it requires an inexpensive and efficient electrocatalyst for the reaction.Transition metal sulfides and phosphates are widely concerned because of their high electrochemical activity,good chemical stability and easy preparation.Therefore,the transition metal sulfides and phosphates were prepared on the nickel foam substrate,and their properties of hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）were studied.The main research contents are as follows:（1）The self-supporting electrode of Ni₃S₂nanowire modified by Mo S₂hollow sphere was prepared by hydrothermal method using NF as the conductive carrier and nickel source without additional template,surfactant or annealing.In this three-dimensional（3D）heterostructure,the ultrathin-layered Mo S₂hollow nanospheres contribute to the promotion of the total surface area and the electrochemical active sites.Meanwhile,the Ni₃S₂nanowires are beneficial to the high electrical conductivity.Consequently,the optimized Mo S₂/Ni₃S₂/NF-200-24 electrocatalyst presents an extremely superior HER activity to that of individual Mo S₂/NF and Ni₃S₂/NF.In HER,when the current density is 10 m A cm^-2,the overpotential is only 85 m V,with good stability.（2）Self-supporting electrode of Co Ni₂S₄/NF hollow nanotube was synthesized on NF substrate by one-step hydrothermal method.The controllable preparation of bimetallic sulfide was realized by adjusting the feed ratio of Co to Ni and the temperature of hydrothermal reaction.Co Ni₂S₄/NF-2-180 material exhibited optimal performance of HER and OER with good stability.（3）Mo-Ni₂P/NF nanowire self-supporting electrode was prepared on NF substrate by hydrothermal and phosphating.The optimal Mo-Ni₂P/NF-0.8-450 catalyst was obtained by optimizing the experimental conditions.In 1 M KOH solution,when the current density is 10 m A cm^-2,the HER overpotential of Mo-Ni₂P/NF-0.8-450 is only48 m V.At a current density of 50 m A cm^-2,its OER overpotential is 357 m V.