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

Photocatalytic degradation of indoor VOCs has great prospects for addressing human health issues in daily life. Here, TiO 2 containing fluorine ions (F − ) on the surface was reduced by hydrogen to obtain the oxygen vacancy-rich sample F-TiO 2−x , which exhibited excellent performance in the photocatalytic VOCs degradation. The characterization results showed that the strong electron repulsion between F − and Ti 3+ encouraged metallization to promote photogenerated charges separation. The DFT calculation results proved that the F − on the surface of TiO 2 was beneficial to the formation of surface oxygen vacancies, and the synergistic effect of oxygen vacancies and F − on F-TiO 2−x could improve the adsorption and activation of H 2 O 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. • F-TiO 2−x showed efficient photocatalytic activity toward multiple indoor VOCs. • The F – on the surface of TiO 2 promoted the formation of surface oxygen vacancies. • F-TiO 2−x metallization enhanced the separation of h + - e – due to F – and OVs coexisted. • F – and OVs on F-TiO 2−x was beneficial to activate O 2 and H 2 O into·O 2 – and·OH.