Preparation And Electrocatalytic Properties Of Cobalt-based Transition Metal Phosphide Nanomaterials

Hydrogen（H₂）is considered to be a new generation of energy to replace fossil energy.H₂ produced by electrolysis of water is a simple,convenient and green preparation method,the prepared hydrogen has high purity and no need to be purified again.However,the slow kinetics of water electrolysis results in the need for a high overpotential.Therefore,it is necessary to develop non-noble metal catalysts with high catalytic activity and stability to reduce the overpotential in the reaction.Cobalt-based catalysts have been widely studied because of their rich reserves,low price and environmental friendliness.However,cobalt-based catalysts have insufficient active sites during the reaction process and poor adsorption ability for oxygen-containing.To solve these problems,we studied the cobalt-based catalysts as follows:1.The porous cobalt phosphide nanofiber catalyst was synthesized by electrospinning and heat treatment.During the catalytic reaction,the electrolyte can enter the catalyst from the porous structure,the catalyst can expose more active sites.As a result,catalyst showed that the overpotential is 93 m V at the current density of 10m A/cm²,and the catalyst had good stability in alkaline solution.2.The Fe OOH@CoP nanofiber catalyst was prepared by coating porous CoP nanofibers with Fe OOH.Decorating CoP with Fe OOH not only optimized the adsorption ability for oxygen-containing intermediates effectively and facilitated electron transfer but also provided abundant active sites to catalyze OER,resulting in a significant enhancement in the activity.Electrochemical tests show that Fe OOH@CoP nanofiber catalyst has an overpotential of 250 m V at the current density of 10 m A/cm²,and the catalyst had good stability in alkaline solution.3.The introduction of Fe in CoP can redistribute the electron and facilitated electron transfer,leading to the enhanced OER activity.