Activity promotion of core and shell in multifunctional core-shell Co2P@NC electrocatalyst by secondary metal doping for water electrolysis and Zn-air batteries

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论文题目:Activity promotion of core and shell in multifunctional core-shell Co2P@NC electrocatalyst by secondary metal doping for water electrolysis and Zn-air batteries

论文作者:Xianwei Lv, Weishan Xu, Wenwen Tian, Haoyu Wang, Zhongyong Yuan*

发表期刊:Small, 17(38), 2101856, 2021   

Abstract: 

Developing cost-efficient multifunctional electrocatalysts is highly  critical for the integrated electrochemical energy-conversion systems  such as water electrolysis based on hydrogen/oxygen evolution reactions  (HER/OER) and metal-air batteries based on OER/oxygen reduction  reactions (ORR). The core-shell structured materials with transition  metal phosphide as the core and nitrogen-doped carbon (NC) as the shell  have been known as promising HER electrocatalysts. However, their  oxygen-related electrocatalytic activities still remain unsatisfactory,  which severely limits their further applications. Herein an effective  strategy to improve the core and shell performances of core-shell  Co2P@NC electrocatalysts through secondary metal (e.g., Fe, Ni, Mo, Al,  Mn) doping (termed M-Co2P@M-N-C) is reported. The as-synthesized  M-Co2P@M-N-C electrocatalysts show multifunctional HER/OER/ORR  activities and good integrated capabilities for overall water splitting  and Zn-air batteries. Among the M-Co2P@M-N-C catalysts, Fe-Co2P@Fe-N-C  electrocatalyst exhibits the best catalytic activities, which is closely  related to the configuration of highly active species (Fe-doping Co2P  core and Fe-N-C shell) and their subtle synergy, and a stable carbon  shell for outstanding durability. Combination of electrochemical-based  in situ Fourier transform infrared spectroscopy with extensive  experimental investigation provides deep insights into the origin of the  activity and the underlying electrocatalytic mechanisms at the  molecular level.