Hollow-structured TiO2 has attracted much attention owing to its low density, good light-reflecting ability, and excellent permeability. However, the wide bandgap (about 3.2 eV for anatase TiO2) and fast recombination of photo-generated carriers hamper its practical application. Herein, oxygen vacancy (OV) was introduced onto the surface of TiO2 hollow microspheres (TiO2-HMSs) by a facile method through calcination of the mixture of hydrogen titanate hollow microspheres (H2TiO3-HMSs) and urea. Using this strategy, both the aims of extending the light-response range and promoting the separation of photo-generated carriers were satisfactorily achieved. The introduction of Ov facilitates the adsorption and activation of NO and O2 on the surface of TiO2-HMSs. This stimulates the production of reactive oxygen species, such as superoxide radicals ([rad]O2 −) and hydroxyl radicals ([rad]OH), resulting in the dramatic promotion of visible-light photocatalytic oxidation of NO.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by the National Natural Science Foundation of China (51672312 & 21373275) and the Fundamental Research Funds for the Central Universities, South-Central University for Nationalities (CZT19006).