Selectively anchoring Pt single atoms at hetero-interfaces of γ-Al2O3/NiS to promote the hydrogen evolution reaction

Single-atom doping plays a vital role in catalysis by maximally taking advantage of atom efficiency. Herein, we report for the first time a new concept of selective single-atom doping with high loading via the crystal-lattice mismatch of a multicomponent hetero-nanostructure. Hetero-nanostructures, with exceptional properties, bring numerous vacancy defects or voids in the hetero-interfaces between the two different components, which can trap more atoms. In this work, single Pt atoms with an ultrahigh loading density of 2.8 wt% are selectively anchored on NiS in a three-dimensional flower-like NiS@Al2O3 heterostructure. This novel strategy can be expanded to a series of transition metal sulfide (TMS, NiS2, CoS2, and MnS) composites with large crystal-lattice mismatch. Pt atom doping remarkably enhances the catalytic performance. The Pt/NiS@Al2O3 exhibits an extremely high catalytic activity in the hydrogen evolution reaction, with a low overpotential of 34 mV and an excellent stability with a 2% increase in overpotential following 120 h under a constant density of 10 mA cm−2.