A new approach to prepare Ti3+ self-doped TiO2 via NaBH4 reduction and hydrochloric acid treatment

Ti3+ doped TiO2 exhibits high photoctalytic activity under the visible light irradiation, owning to the formation of [Ov
- Ti3+]+ inside the bandgap of TiO2, which is beneficial to the production of OH
- and other active groups. Interestingly, the HCl washing treatment further improves the photocatalytic activity of Ti3+ doped TiO2 both under the UV and visible light irradiation.