Hybrid 0D–2D black phosphorus quantum dots–graphitic carbon nitride nanosheets for efficient hydrogen evolution

Abstract As an emerging post-graphene two-dimensional (2D) nanomaterial, black phosphorus (BP) is attracting a great deal of current attention for the direct conversion of solar energy into solar fuels on account of its unique tunable direct-bandgap and high charge-carrier mobility. Herein, for the first time, we immobilize BP quantum dots (BPQDs) onto graphitic carbon nitride (g-C3N4) nanosheets to create a 0D-2D inorganic-organic hybrid via a conventional and cost–effective sonication approach. The as-prepared BPQDs/g-C3N4 hybrids display BPQD content-dependent performance in visible-light-driven hydrogen generation. 5 wt% BPQDs/g-C3N4 with cyclability exhibits the greatest hydrogen evolution rate of 271 μmol h−1 g−1 that is 5.6 and 4.2 times greater than that of pristine g-C3N4 and BPQDs, respectively. We demonstrate that the type-II band alignment, the formation of phosphorus–carbon bonds and the efficient interfacial charge separation between well-dispersed BPQDs and g-C3N4 synergetically enhance the photoactivity and photostability. This study opens possibilities to create viable BP-based heterostructures for energy conversion and storage.