Preparation And Properties Of Self-Supporting Transition Metal Compound Electrocatalyst

Hydrogen energy has great potential to replace fossil energy because of its high energy density and no pollution in practical application.Hydrogen production from electrolytic water is one of the cleanest,safest and most efficient ways to produce hydrogen.The most commonly used catalysts for hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）are precious metal catalysts.However,precious metal catalysts are expensive and need to be coated on the electrode with binder during catalytic reaction,which will block the active sites,affect electron transfer,and have poor durability.Therefore,it is imperative to explore the self-supporting non-precious metal electrocatalyst with high catalytic activity.In this work,the self-supporting transition metal compound electrocatalyst with excellent catalytic performance is designed and prepared by using the methods of heteroatom doping and heterostructure construction,mainly including the following contents:1)Preparation and electrocatalytic properties of CoMoNi SFirst,CoMoNi precursor was grown on foam nickel by simple hydrothermal reaction and then sulfurized to synthesize CoMoNi trimetal sulfide electrocatalyst（CoMoNi S）.CoMoNi S electrocatalyst delivers excellent bifunctional activity 1 M KOH solution.It only needs 1.58 V to drive 10 m A cm^-2current density in the water splitting device,which is lower than that of Pt/C and Ru O₂（1.62 V）.The results of material characterization analysis and electrochemical test show that the high catalytic activity of CoMoNi S comes from its multiple heterogeneous interfaces,which makes the catalyst obtain more active sites,faster charge transfer speed and faster reaction kinetics.Compared with bimetallic sulfide with single heterogeneous interface,constructing a trimetal sulfide catalyst with multiple heterogeneous interfaces can obtain better catalytic performance.This work provides a reference for the follow-up study of multimetallic sulfide.2)Preparation and electrocatalytic properties of Cr-Co P/Ni Co-LDHNiCo bimetallic hydroxide shell coated Cr doped Co P electrocatalyst（Cr-Co P/Ni Co-LDH）grown on foam nickel was fabricated with hydrothermal,phosphating and subsequent electrodeposition.During HER,Cr-Co P/Ni Co-LDH only need the overpotential of 49 m V and 115 m V to drive a high current density of 10 m A cm^-2and 100 m A cm^-2under 1 M KOH solution.There is no obvious performance degradation after consecutive operation for 45 h at high current density of 100 m A cm^-2.This provides a solid support for the subsequent industrialization of the catalyst.The results of material characterization analysis and electrochemical test show that the high catalytic activity of Cr-Co P/Ni Co-LDH catalyst is due to the doping of Cr and the construction of heterogeneous interface,which makes the catalyst obtain more active sites,good conductivity and rapid reaction kinetics;Cr doping and coating of Ni Co-LDH shell improved the stability of Cr-Co P/Ni Co-LDH catalyst.This work demonstrates a general strategy for the design and synthesis of heteroatom doping and heterogeneous interface construction catalysts to improve HER catalytic activity.