Ultrathin layered 2D/2D heterojunction of ReS2/high-crystalline g-C3N4 for significantly improved photocatalytic hydrogen evolution

Abstract

Fabricating efficient nanocatalysts with excellent visible light response, coupled with rapid charge separation and transfer efficiency is still the most challenge for solar-driven hydrogen (H2) evolution. Herein, an ultrathin layered 2D/2D van der Waals heterojunction of ReS2/high-crystalline g-C3N4 (CCN) is constructed for the first time to significantly boost photocatalytic H2 production. The as-prepared optimized 15% ReS2/CCN exhibits the highest H2-evolution rate of 3.46 mmol g−1h−1 under visible light irradiation, a 2.7 fold enhancements over that of pristine CCN and is also much higher than ReS2 alone. The excellent photocatalytic performance of ReS2/CCN is mainly attributed to the efficient charge transport of highly crystalline CCN by eliminating deep defects, the strong visible light harvesting of ReS2 nanoflakes, as well as the synergistic effect of an ultrathin layered 2D/2D heterojunction to rapidly enable charge-separation while inhibiting the charge recombination. This work provides an efficient photocatalyst for H2 energy production, and sheds light on fundamental insight to a rational design of photo/electro nanocatalysts or heterojunction materials toward highly efficient photocatalyst.