Stabilized Co Single-Atom Catalyst via Ion Implantation for Efficient Hydrogen Production.

Although single-atom catalysts (SACs) are garnering significant attention due to their exceptional catalytic properties, the synthesis of SACs remains challenging due to their thermodynamic instability. Herein, stabilized Co-based SACs enabled by the ion implantation technique are presented. It is revealed that implantation of Co ions with an accelerating energy of 120 keV and a controlled fluence not only leads to the formation of stabilized Co single atoms without notable aggregation of Co atoms into nanoclusters, but also induces the creation of defects in the NiO support, such as oxygen vacancies. With the effect of atomically dispersed Co metals over the defective NiO support, the Co single atom-supported NiO catalyst exhibits excellent electrocatalytic performance for hydrogen evolution reaction, showing significantly improved activity as well as stability with negligible catalytic degradation during long-term operation. Cu, Ni, and Fe-based SACs are further successfully synthesized, demonstrating that the ion implantation technique is a universal strategy for the synthesis of SACs with a wide variety of combinations of available metal atoms and supporting materials. This finding can pave the way for the development of stabilized SACs toward efficient and practical sustainable energy conversion systems that are based on various catalytic reactions.