The Influence of Reaction Temperature on the Formation and Photocatalytic Hydrogen Generation of (001) Faceted TiO₂ Nanosheets

Abstract The rapid depletion of fossil fuel reserves has triggered an urgent need for developing clean energy solutions, for example, using sunlight to produce hydrogen with benign photocatalysts. The discovery of (001) faceted TiO₂ has inspired intensive studies of this model photocatalyst. Here, we found that the reaction temperature plays an important role in the formation and photocatalytic activity of TiO₂ nanosheets. Small anatase TiO₂ nanoparticles are formed at low temperatures, large anatase TiO₂ nanosheets appear along with some TiOF₂ crystals as the temperature increases, and pure (001) faceted TiO₂ nanosheets are formed at high temperatures. The photocatalytic activity of the TiO₂ nanoparticles/nanosheets in hydrogen generation increases when the temperature increases. The (001) facet of TiO₂ shows better photocatalytic activity over other facets, and the best performance in hydrogen generation is achieved with synergistic effects between TiO₂ nanosheets and TiOF₂ particles.