Vacuum-treated titanium dioxide nanocrystals: Optical properties, surface disorder, oxygen vacancy, and photocatalytic activities
•Vacuum-treated TiO2 nanocrystals displayed apparent color changes.•Ti3+ and oxygen vacancy defects existed in vacuum-treated TiO2 nanocrystals.•Vacuum temperature had a complicated relationship with the defect contents.•Oxygen vacancy benefited photocatalytic methylene blue (MB) decomposition.•Oxygen vacancy and Ti3+ defects harmed the photocatalytic hydrogen generation.
In this study, we investigated vacuum-treated TiO2 nanocrystals. They displayed long-wavelength optical absorption due to the existence of oxygen vacancy and Ti3+ defects, and also possibly the surface structural disorder. Both oxygen vacancy and Ti3+ defects influenced the photocatalytic activities in methylene blue decomposition and hydrogen generation. Oxygen vacancy benefited photocatalytic methylene blue (MB) decomposition, but harmed the photocatalytic hydrogen generation. Ti3+ defects displayed a more complicated effect.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (113 K)Download as PowerPoint slide
Journal: Catalysis Today - Volume 225, 15 April 2014, Pages 2–9