The Controllable Structure And Catalytic Properties Of Cobalt Phosphide-based Electrocatalysts

Water electrolysis consists of two half-cell reactions:a hydrogen evolution reaction?HER?for generating hydrogen at the cathode,and an oxygen evolution reaction?OER?at the anode for generating oxygen,while increasing the efficiency in the HER and OER of the non-precious metal electrocatalyst is an arduous task.This paper is devoted to the preparation of electrocatalysts by simple methods and inexpensive transition metals.Among them,cobalt phosphide-based catalysts have good electrocatalytic hydrogen production and oxygen production performance.The chaptert three of this paper mainly explores the self-supporting iron-doped cobalt phosphide catalyst.The precursor was synthesized by hydrothermal method,followed by high temperature phosphating to obtain Fe-CoP/NF.The effects of different doping amounts of iron and different reaction time on the catalytic materials were investigated.The catalytic performance was best when the reaction time of 1 mmol FeCl₃·6H₂O was 10 h,and the hydrogen evolution was carried out under alkaline conditions.At the current density of 10 mA cm^-2,the overpotential is 97 mV.At current density of 50 mA cm^-2,the overpotential is 305.7 mV.Electrocatalytic hydrogen evolution under acidic conditions,the corresponding overpotential is 116 mV at a current density of 10 mA cm^-2.The synthesis method the chapter four of this paper is the same as of the chapter three.The NiCoP/NF catalyst was synthesized by optimizing the reaction conditions.At the reaction condition of 90?for 19 h,under acidic conditions,the HER has a current density of 10 mV cm^-2,the overpotential is 113.35 mV.Under alkaline conditions,the HER density is 10 mV cm^-2,and the overpotential is 111.43 mV.Doping Ni element and adjusting the morphology of the catalyst improve the electrocatalytic hydrogen production performance of the catalyst due to the exposure of more active sites under this reaction condition.