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

Photocatalytic reduction of CO 2 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 (SnS 2 /TiO 2 ) to proffer a highly ameliorated effect on the photocatalysis. The catalyst was prepared by hydrothermally depositing ultrathin SnS 2 nanosheets onto TiO 2 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 SnS 2 is 5 wt %, the activity of 2D–2D SnS 2 /TiO 2 catalyst exhibits the optimum catalytic activity with the CH 4 yield of 23 μmol/g, which is 20, 10, and 9 times greater than that conducted by P25, TiO 2 nanosheet, and SnS 2 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.