2D ultrathin ZnIn2S4 nanosheets anchored on octahedral TiO2/Ti3C2 Z-scheme heterostructure for enhanced photocatalytic CO2 reduction

The low carbon dioxide (CO2) conversion efficiency of semiconductor heterojunction-based photocatalysts is a lingering issue in the field of solar energy-driven catalysis. In this study, sandwich-like hierarchical hetero-structures of two-dimensional (2D) ultrathin ZnIn2S4 nanosheets and octahedral titanium dioxide (TiO2) nano-particles were grown in situ on Ti3C2 MXene via a hydrothermal method. Significantly, the ZnIn2S4@TiO2/Ti3C2 ternary heterostructure shows better CO2 reduction activity and the optimal catalyst has carbon monoxide (CO) and methane (CH4) production rates of 59.8 and 23.44 & mu;mol g  1, respectively, within 8 h of simulated solar light illumination, which was greater than that pristine ZnIn2S4. These ultrathin ZnIn2S4 nanosheets and TiO2/Ti3C2 Schottky-junctions assisted the heterostructures to reduce photogenerated electron-hole recombination and in-crease photogenerated charge-transfer and separation in a Z-scheme pathway. ZnIn2S4@TiO2/Ti3C2 hetero-structure photocatalysts have superior photocatalytic CO2 conversion and good stability compared to pure ZnIn2S4. Thus, the suggested approach is to design a highly-efficient photocatalyst for environmental remediation.

Automated summary

In this study, a sandwich-like hierarchical hetero-structure of ZnIn2S4 nanosheets and TiO2 nanoparticles grown on Ti3C2 MXene was synthesized via a hydrothermal method. The ZnIn2S4@TiO2/Ti3C2 ternary heterostructure exhibited enhanced CO2 reduction activity compared to pristine ZnIn2S4, with CO and CH4 production rates of 59.8 and 23.44 μmol g-1, respectively, within 8 hours of simulated solar light illumination. The ultrathin ZnIn2S4 nanosheets and TiO2/Ti3C2 Schottky-junctions facilitated photogenerated charge-transfer and separation, leading to improved photocatalytic CO2 conversion and stability.