Formation of Hierarchical In₂S₃–CdIn₂S₄ Heterostructured Nanotubes for Efficient and Stable Visible Light CO₂ Reduction

Abstract

We demonstrate rational design and fabrication of hierarchical In₂S₃-CdIn₂S₄ heterostructured nanotubes as efficient and stable photocatalysts for visible light CO₂ reduction. The novel self-templated strategy, including sequential anion- and cation-exchange reactions, integrates two distinct sulfide semiconductors into hierarchical tubular hybrids with homogeneous interfacial contacts and ultrathin two-dimensional (2D) nanosheet subunits. Accordingly, the hierarchical heterostructured nanotubes facilitate separation and migration of photoinduced charge carriers, enhance the adsorption and concentration of CO₂ molecules, and offer rich active sites for surface redox reactions. Benefiting from these structural and compositional features, the optimized hierarchical In₂S₃-CdIn₂S₄ nanotubes without employing noble metal cocatalysts in the catalytic system manifest remarkable performance for deoxygenative reduction of CO₂ with high CO generation rate (825 μmol h^-1 g^-1) and outstanding stability under visible light irradiation.