Ultra-thin anatase TiO2 nanosheets dominated with {001} facets: thickness-controlled synthesis, growth mechanism and water-splitting properties

Ultra-thin anatase TiO2 nanosheets with dominant {001} facets (similar to 82%) and controllable thickness (1.6-2.7 nm) were synthesized by using a modified one-pot hydrothermal route. As a morphology controlling agent, the concentration of hydrofluoric acid has a significant impact on the thickness of the as-synthesized TiO2 nanosheets. In addition, according to the XRD patterns and TEM images of the products on different reaction stages, the growth process of TiO2 nanosheets was clarified for the first time. We further measured the efficiency for H-2 evolution of the ultra-thin anatase TiO2 nanosheets loaded with 1 wt% Pt from photochemical reduction of water in the presence of methanol as a scavenger. The TiO2 nanosheets exhibited a H-2 evolution rate as high as 7381 mu mol h(-1) g(-1) under UV-vis light irradiation, attributing to their exposed reactive {001} facets and high crystallinity.