Constructing Atomic Heterometallic Sites in Ultrathin Nickel-Incorporated Cobalt Phosphide Nanosheets via a Boron-Assisted Strategy for Highly Efficient Water Splitting

Abstract

Identification of active sites for highly efficient catalysts at the atomic scale for water splitting is still a great challenge. Herein, we fabricate ultrathin nickel-incorporated cobalt phosphide porous nanosheets (Ni-CoP) featuring an atomic heterometallic site (NiCo16-xP6) via a boron-assisted method. The presence of boron induces a release-and-oxidation mechanism, resulting in the gradual exfoliation of hydroxide nanosheets. After a subsequent phosphorization process, the resultant Ni-CoP nanosheets are implanted with unsaturated atomic heterometallic NiCo16-xP6 sites (with Co vacancies) for alkaline hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The optimized Ni..