Metal-free B-doped graphene with efficient electrocatalytic activity for hydrogen evolution reaction

Abstract

The chemical and physical properties of carbon nanomaterials such as graphene can be tailored by doping their structures with heteroatoms. However, substitutional doping of heteroatoms within carbon nanomaterials requires not only rational synthetic methods but also heteroatom-doping reagents that are easier to employ. Herein we report a facile, wet chemical synthetic method to metal-free, yet catalytically active, B-substituted graphene (B-SuG) by using BH₃-THF—a simple and commercially available borylation reagent. Moreover, we show that the B-doped material (i.e., B-SuG) can serve as an efficient metal-free electrocatalyst for hydrogen evolution reaction (HER). Additionally, we demonstrate that BH₃-THF is a better borylating agent in terms of producing the most effective electrocatalyst than other borylating agents such as NaBH₄, B(OH)₃, carborane, B₂O₃ and NH₃-BH₃. Compared with the conventional heteroatom-doping methods used for graphene, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), BH₃-THF certainly also has the added advantage of being more amenable and easier to use. We expect that this work will stimulate future research on synthesis of other innovative and sustainable metal-free materials and catalysts and investigation of the fundamental structure–property relationships in metal-free catalysts/catalysis for renewable energy and other applications.