Co_(2)P/CoP heterostructures with significantly enhanced performance in electrocatalytic hydrogen evolution reaction:Synthesis and electron redistribution mechanism  

作　　者：Baoshan Liu Boan Zhong Feng Li Jing Liu Liping Zhao Peng Zhang Lian Gao 

机构地区：[1]School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Nano Research》2023年第11期12830-12839,共10页纳米研究（英文版）

基　　金：supported by the fundings from the National Natural Science Foundation of China(Nos.51972210,52111530187,and 82172443);Medical-Engineering Funding of Shanghai Jiao Tong University(No.YG2021QN91).

摘　　要：Heterostructures are often constructed to modulate the electronic states of the two catalysts,achieving high-performance in alkaline hydrogen evolution reaction(HER).Various mechanisms have been proposed for the heterostructural catalysts,which however awaits further approvement.Herein,a heterostructure composed of Co_(2)P and CoP was successfully prepared with significantly enhanced HER catalytic activity relative to the endmembers.The ultraviolet photoelectron spectroscopy(UPS)and Xray photoelectron spectroscopy(XPS)revealed the effective promotion of the self-driven transferring of electrons from CoP to Co_(2)P and the accumulation of electrons on the P sites in Co_(2)P due to the strong electronic coupling of built-in electric field in the Co_(2)P/CoP interface.In situ electrochemical impedance spectroscopy(EIS)and poison experiments confirmed the Heyrovsky step of H*intermediate depleting on electronegative P sites and contributions of both metal and P to the reactivity in the Co_(2)P/CoP.Density functional theory(DFT)calculations clarify that the electronic structure at interface of the heterojunction significantly weakens the hydrogen adsorption free energy(ΔGH*ads)of P site in Co_(2)P/CoP to near zero.We also propose an electronic redistribution strategy for heterostructures that activates the multiple routes mechanism and production of more active sites.The working mechanism is expected to be further extended to other transition metal compounds for efficient HER activity.

关 键 词：HETEROSTRUCTURE electronic structure active site intermediate depleting density functional theory 

分 类 号：O64[理学—物理化学]