Surface functionalization of phosphorene via P-H bond for ambient protection and robust photocatalytic H2 evolution

Abstract

The facile oxidation of few-layer black phosphorus (i.e., phosphorene) in the atmospheric environment is a major hurdle for its applications in photocatalytic solar-energy conversion. The introduction of protective layers, such as a surface capping layer, surface coordination, and P-C covalent functionalization, can protect phosphorene from oxidative degradation but inevitably decreases its photocatalytic performance due to the blockage of catalytic active sites. Herein, we develop a hydrogenation approach via the introduction of P-H covalent bonds on the surface of phosphorene (i.e., phosphorene-H) to inhibit the oxidation of phosphorene-H without sacrificing the original photocatalytic H2 evolution performance. Experiments and density functional theory calculations demonstrate that about 5 mol% of phosphorus atoms in phosphorene-H are involved in forming P-H covalent bonds, hindering the reaction between O2 and phosphorene-H in terms of thermodynamics and kinetics. This hydrogenation strategy is envisaged to augment the prospect of phosphorene in the field of photocatalysis.