Photocatalytically recovering hydrogen energy from wastewater treatment using MoS2 @TiO2 with sulfur/oxygen dual-defect

Photocatalysis is a promising technology for energy and environment applications. Herein, a dual-defect heterojunction system of TiO2 hierarchical microspheres with oxygen vacancies modified with ultrathin MoS2-x nanosheets (MoS2-x @TiO2-OV) is designed for simultaneously degrading pollutants and evolving hydrogen. MoS2- x @TiO2-OV exhibits a dramatically enhanced photocatalytic activity with a H2 evolution rate of 2985.16 mu mol g- 1h- 1. In treating the simulated pharmaceutical wastewater, MoS2- x @TiO2-OV is capable of purifying various refractory contaminants, with the highest H2 evolution rate of 41.59 mu mol g- 1h- 1 during enrofloxacin degradation. While treating the simulated coking wastewater, the catalyst achieves a H2 evolution rate of 102.72 mu mol g- 1h- 1 and a mineralization rate of 50%. Computational studies suggest that the dual-defect is superior for the adsorption of H* and producing.OH ('dual-defect boosted dual-function'). Also, the dual-defect sites significantly boosted the charge-carrier separation and transfer efficiencies. This work highlights the crucial role of defect engineering to develop the energy-recovering wastewater treatment approaches.

Automated summary

A dual-defect heterojunction system of TiO2 hierarchical microspheres with oxygen vacancies modified with ultrathin MoS2-x nanosheets (MoS2-x @TiO2-OV) was designed for degrading pollutants and evolving hydrogen simultaneously with enhanced photocatalytic activity. The catalyst showed superior performance in treating pharmaceutical and coking wastewater, highlighting the crucial role of defect engineering in developing energy-recovering wastewater treatment approaches.