Core-shell structured Mn3O4@CdIn2S4 microspheres with S-scheme charge transfer route for efficient photocatalytic hydrogen evolution

In this study, core–shell Mn3O4@CdIn2S4 (Mn3O4@CIS) microspheres were prepared via synthesis of Mn3O4 microspheres with Mn-MOF as precursor followed by in-situ growth of CdIn2S4 (CIS) shell. The hydrogen evolution rate of the optimized Mn3O4@CIS was 2.6 mmol·g−1·h−1, which were 11.54-fold and 17.44-fold that of CIS and Mn3O4 alone, respectively. The spherical core–shell structure could broaden the light absorption range and enhance the separation and migration of photogenerated carriers, thereby promoting solar energy utilization. More importantly, experimental and computational results proved that the charge migration followed an S-scheme transfer route in the interface between Mn3O4 and CIS, accumulating photogenerated electrons in the conduction band of CIS for robust photocatalytic hydrogen evolution. This work provided a facile strategy for the design and fabrication of efficient photocatalysts via synchronous morphology and S-scheme heterojunction architecture.