Valence engineering has been proved an effective approach to modify the electronic property of a catalyst and boost its oxygen evolution reaction (OER) activity, while the limited number of elements restricts the structural diversity and the active sites. Also, the catalyst performance and stability are greatly limited by cationic dissolution, ripening, or crystal migration in a catalytic system. Here we employed a widely used technique to fabricate heteroepitaxial pyrite selenide through dual-cation substitution and a boron dopant to achieve better activity and stability. The overpotential of Ni-pyrite selenide catalyst is decreased from 543 mV to 279.8 mV at 10 mA cm-2 with a Tafel slope from 161 to 59.5 mV dec-1. Our theoretical calculations suggest both cation and boron doping can effectively optimize adsorption energy of OER intermediates, promote the charge transfer among the heteroatoms, and improve their OER property. This work underscores the importance of modulating surface electronic structure with the use of multiple elements and provides a general guidance on the minimization of activity loss with valence engineering.

Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong People's Republic of China

Institute of Surface Micro and Nano Materials Xuchang University Xuchang Henan 461002 People's Republic of China

Regional Center of Advanced Technologies and Materials Olomouc 78371 Czech Republic

School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 People's Republic of China

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Single Atom Catalysts Based on Earth-Abundant Metals for Energy-Related Applications