Fluorine-induced oxygen vacancies on TiO2 nanosheets for photocatalytic indoor VOCs degradation

Abstract

Photocatalytic degradation of indoor VOCs has great prospects for addressing human health issues in daily life. Here, TiO2 containing fluorine ions (F−) on the surface was reduced by hydrogen to obtain the oxygen vacancy-rich sample F-TiO2−x, which exhibited excellent performance in the photocatalytic VOCs degradation. The characterization results showed that the strong electron repulsion between F− and Ti3+ encouraged metallization to promote photogenerated charges separation. The DFT calculation results proved that the F− on the surface of TiO2 was beneficial to the formation of surface oxygen vacancies, and the synergistic effect of oxygen vacancies and F− on F-TiO2−x could improve the adsorption and activation of H2O molecules, which was also effective for oxygen molecules. All of these were beneficial to the formation of active free radicals. Moreover, the presence of surface F- could effectively promote the stabilization of oxygen vacancies.