Z-Scheme Core-Shellmeso-TiO₂@ZnIn₂S₄/Ti₃C₂MXene Enhances Visible Light-Driven CO₂-to-CH₄Selectivity

Solar photocatalysis has long relied on the rational design of semiconductor photocatalysts. Herein, a ternarymeso-TiO₂@ZnIn₂S₄/Ti₃C₂MXene photocatalyst is prepared and demonstrated with a core-shell structure accompanied by few-layered Ti₃C₂Mxene on the ZnIn₂S₄shell. The success of the synthesis depends on a two-step method consisting of hydrothermal and electrostatic self-assembly procedures. The ternary heterojunction exhibits a good behavior for photocatalytic CO₂reduction. A mechanism study of the photocatalytic reaction indicates that the photogenerated charges transfer in a Z-scheme pathway. Moreover, the construction of the Schottky junction between metallic Ti₃C₂and TiO₂@ZnIn₂S₄is extremely effective for the reduction reaction. Consequently, the photocatalytic rates toward CO and CH₄production are up to 30.5 and 34.0 μmol/g within 3 h of illumination by simulated sunlight, respectively, while the CH₄selectivity reaches 52.7%. This work provides a good strategy to achieve highly efficient photocatalytic CO₂reduction.