Formation of Hierarchical FeCoS2–CoS2 Double‐Shelled Nanotubes with Enhanced Performance for Photocatalytic Reduction of CO2

Abstract Hierarchical FeCoS 2 –CoS 2 double‐shelled nanotubes have been rationally designed and constructed for efficient photocatalytic CO 2 reduction under visible light. The synthetic strategy, engaging the two‐step cation‐exchange reactions, precisely integrates two metal sulfides into a double‐shelled tubular heterostructure with both of the shells assembled from ultrathin two‐dimensional (2D) nanosheets. Benefiting from the distinctive structure and composition, the FeCoS 2 –CoS 2 hybrid can reduce bulk‐to‐surface diffusion length of photoexcited charge carriers to facilitate their separation. Furthermore, this hybrid structure can expose abundant active sites for enhancing CO 2 adsorption and surface‐dependent redox reactions, and harvest incident solar irradiation more efficiently by light scattering in the complex interior. As a result, these hierarchical FeCoS 2 –CoS 2 double‐shelled nanotubes exhibit superior activity and high stability for photosensitized deoxygenative CO 2 reduction, affording a high CO‐generating rate of 28.1 μmol h −1 (per 0.5 mg of catalyst).