Elemental sulfur supported on ultrathin titanic acid nanosheets for photocatalytic reduction of CO2 to CH4

The photocatalytic reduction of CO2 into energy-intensive hydrocarbon fuels is promising to solve environment and energy issues. Here, elemental sulfur supported on ultrathin titanic acid nanosheets (S/HTO) heterostructure is designed and synthesized by loading different weight contents of elemental S on HTO nanosheets via a simple in-situ disproportionation-assembly process. The as-designed S/HTO heterostructure not only enhances light absorption and facilitates CO2 adsorption, but also significantly promotes the interfacial charge transport, and suppresses the recombination of photogenerated charge carriers. As a consequence, the as-prepared S/HTO heterostructure exhibits enhanced performance in photocatalytic CO2 reduction under simulated solar light illumination. A CH4 yield rate of 1.92 μmol h−1 g−1 is obtained over the optimal 15S/HTO composite without the using of cocatalyst and sacrificial agent. The photoactivity is 5.4-fold and 23-fold larger than that of HTO nanosheets and blank S, respectively. In addition, the S/HTO hybrid composite also presents high stability for the production of CH4.