One-step synthesis of 2D/2D gC₃N₄/MoS₂ composites for effective photocatalytic hydrogen evolution

Two-dimensional (2D) heterostructures have proven their efficiency in separating charges. Herein, a gC₃N₄/MoS₂ (CN/MoS₂) photocatalyst, in the form of 2D/2D van der Waals heterojunction with a type-II band alignment, was synthesized using a novel one-step method. The resulting in-situ formed heterojunction interface enhances electron transfer from gC₃N₄ to MoS₂. The CN/MoS₂ photocatalyst exhibits exceptional activity in generating hydrogen from water under simulated solar light. Its hydrogen production rate was 1285 μmol/h/g, which was approximately 3 times higher compared to gC₃N₄. This superiority is due to a significant increase in photogenerated carrier density and efficient charge separation facilitated by the type-II heterojunction. This study demonstrates a straightforward one-step approach for synthesizing 2D/2D composite photocatalysts, highlighting the effective synergy between different 2D materials in promoting hydrogen generation.