Ionic Liquid Dopant Induced Abundant Ni-Vacancies in N, B, F Tri-Doped NiSe2/Mo2CTx Stabilizing of Single-Atom Ru for Efficient Hydrogen Evolution Reactions and Flexible Zn–Air Batteries

Cation vacancies are essential for stabilizing single atoms, but there is relatively little research on how to generate large numbers of cation vacancies. In this study, we present a method for doping transition metal compounds (NiSe2) loaded on Mo2CTx with heteroatoms. Ionic liquids were used to create cationic vacancies in NiSe2 to successfully stabilize a dense Ru single-atom (Ru/NBF-NiSe2/Mo2CTx), which exhibited overpotentials of 30 and 39 mV in acidic and alkaline solutions at a current density of 10 mA cm–2. What is more, Ru/NBF-NiSe2/Mo2CTx had the lowest overpotential (1.558 V) in the OER test at a current density of 10 mA cm–2 and a high half-wave potential (0.912 V) in the ORR test at 1600 rpm. It also has excellent performance when constructed into Zn–air batteries. This design provides a simple technique for creating cationic vacancies to stabilize single atoms in transition-metal compounds.