Nanostructure Control Of Iron-based Metal Sulfides And Its Electrocatalytic Oxygen Evolution Reaction

For adapting to modern society's energy demand,mankind has been trying to seek sustainable the technology of the clean energy conversion and storage.The reason of restricting energy conversion efficiency is the sluggish reaction kinetics of oxygen evolution reaction(OER),which applies to electric water decomposition hydrogen,metal air batteries,fuel cells and other clean energy transformation and storage technology.Combining the theoretical calculation and experimental test,to comprehending OER mechanism and designing the synthesis of highly active OER the electricity catalyst has important scientific significance for improving OER the catalytic efficiency.Basing on the ferro-serial sulfides electrocatalytic performance,we tried to use different controllable method to compound cobalt sulfide and different current collector to improve electrical conductivity.The results of the experiment test combining with density functional theory(DFT)calculation explore cobalt sulfide phase,composition and the surface defects influence for OER activity.The research contents of this paper are as follows:1,We use oleylamine-cobalt coordination compound as metal source and sodium sulfide as sulfur source to assemble cobalt sulfide in the oil-water two phase interface,then which go through solvent thermal and maturation process to compound the weak crystal Co3S4 nanosheet.The composition characterization of the nanometer characteristics are revealed by XRD,Raman.XPS and SEM results reveal the structure characteristics of the material.We discusse the composite conditions of Co3S4 nanosheet for the influence on OER performance through electrochemical test.2,We use two step synthesis "grain" shape Co9S8 array(Co9S8/F-Ni)on nickel foam.First,we successfully use solvent thermal method to synthesize Co3O4 nanowires array on the surface of nickel foam:With sulphur imidazole as sulfur source,basing on Co-S coordination effect,they formed Co9S8/F-Ni precursorin the surface of nickel foam.After inert atmosphere heat treatment,we obtained the "grain" shape Co9S8/F-Ni.Compared with powder materials,we explore the influence of conductive basement for the transition metal sulfides of oxygen evolution activity.3,Co1-xS nanosheets were designed and grown on reduced graphene oxide(rGO)by controlling the successive two-step hydrothermal reaction.We adjust the shape and size of Co1-xS by controlling the reaction and discussed the formation mechanismCo1-xS nanosheets.XPS verifies the characterization of Co absence.Density functional theory calculations prove that the absence of Co is OER the catalytic active center.The performance test results show that the absence of Co and lamellar structure can effectively improve the OER electrocatalytic efficiency.