Construction of ZnIn₂S₄–In₂O₃ Hierarchical Tubular Heterostructures for Efficient CO₂ Photoreduction

We demonstrate the rational design and construction of sandwich-like ZnIn₂S₄-In₂O₃ hierarchical tubular heterostructures by growing ZnIn₂S₄ nanosheets on both inner and outer surfaces of In₂O₃ microtubes as photocatalysts for efficient CO₂ photoreduction. The unique design integrates In₂O₃ and ZnIn₂S₄ into hierarchical one-dimensional (1D) open architectures with double-heterojunction shells and ultrathin two-dimensional (2D) nanosheet subunits. This design accelerates the separation and transfer of photogenerated charges, offers large surface area for CO₂ adsorption, and exposes abundant active sites for surface catalysis. Benefiting from the structural and compositional merits, the optimized ZnIn₂S₄-In₂O₃ photocatalyst exhibits outstanding performance for reductive CO₂ deoxygenation with considerable CO generation rate (3075 μmol h⁻¹ g⁻¹) and high stability.