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

Hierarchical FeCoS2–CoS2 double‐shelled nanotubes have been rationally designed and constructed for efficient photocatalytic CO2 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 FeCoS2–CoS2 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 CO2 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 FeCoS2–CoS2 double‐shelled nanotubes exhibit superior activity and high stability for photosensitized deoxygenative CO2 reduction, affording a high CO‐generating rate of 28.1 μmol h−1 (per 0.5 mg of catalyst).