| It has become an urgent requirement to search the sustainable and clean energy nowadays. On account of the abundant existence of water and sunlight, photocatalytic water splitting is considered a potential way to transform solar energy into the hydrogen that is renewable and storable. TiO2 is the most widely used semiconductor material owing to its low cost, high stability, and friendliness to the environment. However, some disadvantages limit its further developments. In this work, anatase TiO2 nanosheets mainly exposed (001) facets were synthesized and co-catalysts were loaded through photo-deposition method to improve the photocatalytic activity. The main results includ:1. Anatase TiO2 nanosheets that mainly exposed (001) facets were obtained through a hydrothermal process with Ti(OBu)4 as the precursor and hydrofluoric acid (HF) as the morphology-directing agent. The exposed (001) facets was about 70% through characterization and calculation. Photo-deposition method was used to prepare Ru/TiO2 and RuO2/TiO2 photocatalysts. It was found that Ru and RuO2 nanoparticles were deposited on the different facets of anatase TiO2 nanosheets according to the photocatalytic tests. This phenomenon may be caused by the charge separation effect of anatase TiO2 with the help of previous studies. We further tested the photocatalytic O2 evolution rates of the catalysts after the redox treatments and found that the photocatalytic activities were deeply reduced when the loading co-catalysts were changed. While the activities were covered after the Ru species were changed to the original states. These phenomena further proved the charge separation effect of anatase TiO2 and revealed the roles of Ru species during the photocatalytic process. Based on these results, Ru-RuO2/TiO2 catalyst loaded with dual co-catalysts was engineered through two-stepped photo-depostion methods, which proved a effective way to synthesis the catalysts with high photocatalytic activity.2. Transition metal oxides such as CoOx, MnOx, FeOx were deposited on the anatase TiO2 nanosheets through photo-deposition method. The photocatalytic results proved that the samples loaded CoOx and MnOx nanoparticles exhibited high photocatalytic activities. The sample loaded FeOx nanoparticles also showed the photocatalytic activity. The photocatalytic activity of above samples was improved after deposited with Pt nanoparticels. It proved the role of transition metal oxides during the photocatalytic process and provided a effective way to search the cheap but excellent substitutes of noble metal oxides. |
