Iso‐Elemental ZnIn2S4/Zn3In2S6 Heterojunction with Low Contact Energy Barrier Boosts Artificial Photosynthesis of Hydrogen Peroxide

Abstract

AbstractArtificial photosynthesis emerges as a strategic pathway to produce hydrogen peroxide (H2O2), an environmentally benign oxidant and a clean energy carrier. Nonetheless, in many heterojunction‐based artificial photosynthetic systems, the H2O2 productivity is significantly hindered by poor carrier transport, narrow spectral light absorption, and a lack of adequate active sites for the two‐electron oxygen reduction reaction. Herein, a catalyst architecture with an iso‐elemental heterojunction formed by interfacing Zn3In2S6 nano‐flowers and ZnIn2S4 nanosheets is proposed. This catalyst exhibits a H2O2 production rate as high as 23.47 µmol g−1 min−1 under UV–vis light irradiation, which is attributed to the minimized contact energy barrier and enhanced lattice match at the ZnIn2S4/Zn3In2S6 interface thanks to the iso‐elemental catalyst architecture which aids in enhanced efficient separation and transfer of photogenerated carriers. Theoretical simulations alongside comprehensive in‐situ and ex‐situ characterizations confirm the photo‐redox sites for H2O2 generation and effective carrier dynamics across the catalyst surface. Moreover, substituting one reduction‐type catalyst ZnIn2S4 with other non‐iso‐elemental catalysts like CdIn2S4, TiO2, and CdS further confirms the feasibility and superiority of the proposed iso‐elemental configuration. This work offers a new perspective on designing heterojunction catalysts for artificial photosynthesis of H2O2.