Construction of 2D/1D Cu₇S₄ nanosheets/Mn_0.3Cd_0.7S nanorods heterojunction for highly efficient photocatalytic...

Developing cost-effective cocatalyst-modified photocatalytic systems with boosted carrier separation and rapid surface catalytic reaction is an ideal strategy for effectively converting solar energy into desired fuels. Herein, a series of Cu₇S₄/Mn_0.3Cd_0.7S hierarchical heterostructures are designed and fabricated to achieve efficient and robust photocatalytic H₂ evolution by coupling one-dimensional (1D) Mn_0.3Cd_0.7S nanorods with two-dimensional (2D) Cu₇S₄ nanosheets through a facile sonochemical strategy. Benefiting from dimensionality and cocatalyst effects, the constructed 2D/1D Cu₇S₄/Mn_0.3Cd_0.7S heterojunction photocatalyst containing 1.5 wt% Cu₇S₄ displays excellent photostability and superior photocatalytic H₂ evolution rate up to 914.3 μmol h^-1, which is 4.43 and 2.22-folds increment relative to bare Mn_0.3Cd_0.7S and the 3 wt% Pt/Mn_0.3Cd_0.7S, respectively. The various characterization results reveal that the utilization of semimetallic Cu₇S₄ nanosheets as the cocatalyst to form a Schottky heterojunction can promote the light-harvesting capability, suppress charge carrier recombination, and provide sufficient reaction sites for hydrogen generation, thereby resulting in the dramatically improved photocatalytic performance. This work clarifies the role of Cu₇S₄ nanosheets as the robust and cost-effective cocatalyst in the photocatalytic reaction and opens a new horizon for designing other Cu₇S₄-based cocatalyst/semiconductor Schottky heterostructures for efficient solar-to-fuel conversion.