Molten Salt-Lithium Process Induced Controllable Surface Defects in Titanium Oxide for Efficient Photocatalysis

The efficiency of photoabsorption, photo-generated charge separation, and surface redox reaction determine the overall efficiency of photocatalysts. Therefore, exploring ways to simultaneously optimize the parameters is key to improving the photocatalytic performance. Herein, a novel low-temperature ternary molten salt-lithium reduction method is designed to create controllable oxygen vacancies (Ovs) as well as to manipulate the surface microstructure of the classic photocatalyst TiO2. The optimized TiO2 exhibits a 10-fold increase in the photocatalytic RhB breakdown rate and H2 generation quantity compared to pristine TiO2. The dual surface defects result in synergistic effects: i) Ovs lower band gap, enhance the charge separation efficiency as capture centers, and facilitate hydrogen adsorption; ii) the enlarged surface area enhances light-harvesting and provides more active sites. This research proposes a novel strategy for manipulating surface defects in a controlled manner and highlights the synergistic optimization of the thermodynamical and kinetical parameters to promote the photocatalytic performance.