Synthesis And Performance Of Multimetallic Selenides For Electrocatalytic Water Splitting Based On Prussian Blue Analogue Precursors

With the rapid development of the global economy and the continuous improvement of people’s living standards,the energy crisis and environmental protection problems are also increasing.It is urgent to develop high energy density and clean renewable new energy.Hydrogen is considered to be one of the most promising clean energy sources due to its high calorific value,pollution-free combustion by-products and no greenhouse gas emissions.Electrocatalytic water splitting is one of the most efficient and low-energy hydrogen production technologies.which has the potential for large-scale industrial applications.However,electrolysis of water to produce hydrogen faces the problem of high electrochemical energy barrier,and catalysts need to be introduced to reduce the reaction barrier.Commercial platinum-based and Ir O₂/Ru O₂ catalysts have high catalytic activity for hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）,respectively,but high cost and scarcity restrict their popularization and application.Therefore,the development of cheap,efficient and stable electrocatalysts is of great significance for hydrogen production from water electrolysis.As a cheap metal-organic framework material,Prussian blue has been widely concerned in the field of electrocatalytic water splitting due to its diverse structure,adjustable chemical composition and rich active sites.This paper explores the synthesis of binary and multi-metal electrocatalysts using Ni Co-PBA precursor electrodeposited on carbon fiber paper.Low-temperature selenization reaction was used to create the binary composite metal electrocatalysts,while co-precipitation method was employed to prepare Ni Co and Ni Co Fe-PBA powders.The study systematically examined how microstructure design and composition regulation affect the water splitting performance of electrocatalysts.Furthermore,the paper explores the use of Prussian blue as a precursor to improve the performance of multi-metal selenide electrocatalysts.The Ni Co-PBA precursor with cubic morphology was in-situ grown on CFP by adjusting the parameters such as solution concentration and solution p H value by cyclic voltammetry in the solution containing Ni²⁺and[Co（CN）₆]^3-.Then,Ni Co-Se/CFP nanomaterials with porous interconnection structure were obtained by chemical vapor deposition process by adjusting the selenization temperature and heating rate,and the cubic morphology of the precursor was maintained.In an alkaline environment of p H=14,Ni Co-Se/CFP only needs 216 m V of HER and 308 m V of OER overpotential to drive a current density of 10 m A cm^-2,which is significantly better than that of single metal Co-Se/CFP electrode and Ni Co-PBA/CFP precursor.At the same time,Ni Co-Se/CFP electrocatalysts also show excellent durability in alkaline environments.The exceptional performance of Ni Co-Se/CFP is attributed to its distinctive 3D porous interconnection structure that provides increased access to active sites and facilitates substance transport during the reaction.Additionally,the synergistic effect of Ni and Co enhances electron transfer kinetics and boosts the intrinsic catalytic activity of the electrocatalysts.Ni²⁺/Co²⁺molar ratios in the solution were methodically designed through co-precipitation,resulting in the acquisition of Ni Co Fe-PBA precursor powders with varied molar ratios of Ni²⁺/Co²⁺ions through composition regulation.Following the same chemical vapor deposition process,controllable composition Ni Co Fe-Se powder was produced.The electrocatalytic performance of these powders was assessed on CFP conductive substrates.Ni Co Fe-Se demonstrated optimal electrocatalytic performance when Ni²⁺/Co²⁺had a ratio of1:3,generating a current density of 10 m A cm^-2 with mere overpotentials of 194 m V HER and238 m V OER.Moreover,the corresponding Tafel slopes were impressively low,measuring only 36.9 and 57.1 m V dec^-1,respectively.The electrocatalytic performance of Ni Co Fe-Se powder significantly exceeds that of Ni Co-Se powder,which can be attributed to the synergistic effect of multiphase selenides.The study demonstrates that appropriate composition regulation can enhance the performance of transition metal-based selenide electrocatalysts derived from PBAs precursors.These findings emphasize the potential of transition metal-based selenides as efficient electrocatalysts for water splitting.