Construction of a Two-Dimensional Composite Derived from TiO2 and SnS2 for Enhanced Photocatalytic Reduction of CO2 into CH4

Photocatalytic reduction of CO, does effectively mitigate the concern of environmental issues and energy shortage. As one of the effective techniques for improving photocatalytic performance, highly efficient compounding between semiconductor and cocatalyst is capable of inhibiting electron and hole recombination. Herein, we build a 2D-2D heterojunction photocatalyst (SnS2/TiO2) to proffer a highly ameliorated effect on the photocatalysis. The catalyst was prepared by hydrothermally depositing ultrathin SnS2 nano sheets onto TiO2 nanosheets. The prepared composite is systematically analyzed and confirmed by the corresponding characterizations. Further practical application of the as-synthesized catalysts demonstrates that when the loaded amount of SnS2 is 5 wt %, the activity of 2D-2D SnS2/TiO2 catalyst exhibits the optimum catalytic activity with the CH4 yield of 23 mu mol/g, which is 20, 10, and 9 times greater than that conducted by P25, TiO2 nanosheet, and SnS2 nanosheet, respectively. According to the PL, PEC, and TEM characterization, along with the increment of the contact interface between the two components, the combination of electrons and holes is greatly reduced.