Synergistic role of Cu-C and Cu-N dual bonding of nanostructured g-C3N4/Cu2SnS3 photocatalysts for efficient CO2 conversion to CO

Herein, a 2D/0D g-C3N4/Cu2SnS3 heterostructure is successfully constructed via the facile calcination method, and its application to photocatalytic CO2 conversion is demonstrated for the first time. The fabricated g-C3N4/Cu2SnS3 nanocomposite is featured with its unique Cu-C and Cu-N dual chemical bond at the interface. The engineered g-C3N4/Cu2SnS3 nanocomposites record a superior CO production rate of 18.2 μmol∙g−1∙h−1 with an apparent quantum yield of 2.2% at 500 nm of light illumination, which is the highest among g-C3N4/ternary metal sulfide photocatalysts to the best of our knowledge. This notable improvement is attributed to the effective incorporation of Cu2SnS3 nanoparicles onto the surfaces of ultra-thin g-C3N4 and, the formation of Cu-N and Cu-C dual bonds at the interface. This helps not only the activation of interface defect-mediated Z-scheme conduction but also supplies highly reactive Cu sites in the Cu2SnS3 nanoparticles for efficient photocatalytic CO2 conversion.