Synergy of phosphorus vacancies and build-in electric field into NiCo/NiCoP Mott-Schottky integrated electrode for enhanced water splitting performance  

作　　者：Xiaochen Zhang Hui Xue Jing Sun Niankun Guo Tianshan Song Jiawen Sun Yi-Ru Hao Qin Wang 

机构地区：[1]College of Chemistry and Chemical Engineering,Inner Mongolia University,Hohhot 010021,China

出　　处：《Chinese Chemical Letters》2024年第2期604-610,共7页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(NSFC,Nos.22269015,22205119);Natural Science Foundation of Inner Mongolia Autonomous Region of China(Nos.2021ZD11,2019BS02015).

摘　　要：Vacancy engineering and Mott-Schottky heterostructure can accelerate charge transfer,regulate adsorption energy of reaction intermediates,and provide additional active sites,which are regarded as valid means for improving catalytic activity.However,the underlying mechanism of synergistic regulation of interfacial charge transfer and optimization of electrocatalytic activity by combining vacancy and Mott-Schottky junction remains unclear.Herein,the growth of a bifunctional NiCo/NiCoP Mott-Schottky electrode with abundant phosphorus vacancies on foam nickel(NF)has been synthesized through continuous phosphating and reduction processes.The obtained NiCo/NiCoP heterojunctions show remarkable OER and HER activities,and the overpotentials for OER and HER are as low as 117 and 60 mV at 10 mA/cm^(2) in 1 mol/L KOH,respectively.Moreover,as both the cathode and anode of overall water splitting,the voltage of the bifunctional NiCo/NiCoP electrocatalyst is 1.44 V at 10 mA/cm^(2),which are far exceeding the benchmark commercial electrodes.DFT theoretical calculation results confirm that the phosphorus vacancies and build-in electric field can effectively accelerate ion and electron transfer between NiCo alloy and NiCoP semiconductor,tailor the electronic structure of the metal centers and lower the Gibbs free energy of the intermediates.Furthermore,the unique self-supported integrated structure is beneficial to facilitate the exposure of the active site,avoid catalyst shedding,thus improving the activity and structural stability of NiCo/NiCoP.This study provides an avenue for the controllable synthesis and performance optimization of Mott-Schottky electrocatalysts.

关 键 词：Mott-Schottky Build-in electric field Phosphorus vacancies PHOSPHIDES Overall water splitting 

分 类 号：TQ426[化学工程]