Modification Of Nano-porous Co₉S₈ Electrocatalyst And Its Analysis Of Oxygen Evolution Reaction Properties

With the rapid development of social economy and the continuous increase of population,many problems like environmental pollution and traditional resource depletion become the main problems which restrict the development of the society.Human beings is facing the challenge of developing clean and renewable energy.Transition metal sulfides are widely used in electrolytic water due to its high catalytic performance,corrosion resistance in alkaline solution,simple preparation method and low cost.The products of electrolytic water reaction are hydrogen and oxygen and hydrogen is one of the new energy.In this paper,rods of hexagon prisms of Co₉S₈ and Co₂P were prepared by solvothermal method and the subsequent calcination and they were used to catalyse the oxygen evolution reaction?OER?.Sulfide-Cobalt precursors of hexagon prisms were prepared by solvothermal method,and the effects of different solvothermal conditions on the morphology of precursors and on the catalytic property of the products after sintering were studied.Finally,the optimal solvothermal conditions were determined.In order to improve the stability of the catalyst,pure carbon paper which was treated sulphuric acid was added into the 60 ml Teflon-lined autoclave while preparing the precursor,so that Co₉S₈ can be loaded on the carbon paper to obtain CFP-Co₉S₈ which is a kind of self-supporting electrode.Carbon paper can be used as a base for catalyst due to its structure of smooth and crossed carbon fiber.And carbon paper has the advantages of large surface area,good conductivity and low cost.In order to further improve the crystallinity and purity,CFP-Co₉S₈ was phosphatized to get CFP-Co₂P.The microstructure of the products were determined by scanning electron microscopy?SEM?and transmission electron microscopy?TEM?,and the phase composition of the products were determined by X-ray diffraction?XRD?.Nitrogen adsorption and desorption curves showed that CFP-Co₂P has a higher specific surface area and smaller pore size distribution.The catalytic properties in alkaline solution of the Co₉S₈ power,CFP-Co₉S₈ and CFP-Co₂P were tested by electrochemical workstations.Results showed that the catalytic activity of CFP-Co₉S₈ was higher thanCo₉S₈ powder,and CFP-Co₂P had the highest catalytic performance and stability.Its initial potential of oxygen evolution reaction was 0.42V,and its potential was0.49V when the current density was 10mA/cm².Due to its large active area,high catalytic efficiency and high stability,it has great practical application value.