Self-doped defect-mediated TiO₂ with disordered surface for high-efficiency photodegradation of various pollutants

Photocatalytic technology in eliminating organic pollutants is considered to be one of the most promising technologies to solve environmental issues. However, the low catalytic activity exhibited by Titanium dioxide (TiO₂) limits its further application. In order to enhance the photocatalytic activity, structural regulation of TiO₂ is designed by chemical reduction method to promote the production of massive Ti³⁺ and oxygen vacancies (OVs), these defects can serve as inter-band level of semiconductor to enhance photon capture and transfer efficiency of photogenerated charge. The samples show strong light absorption ability, which leads to excellent photocatalytic activity for various organic pollutants degradation. Results showed robust degradation of MO, RhB, DCP and TC under UV irradiation within 60 min. Estimated quantum yields of as-synthesized TiO₂ systems for removing representative pollutants are calculated, which indicates higher reactivity than commercial TiO₂. The XPS, TEM, photoelectrochemical analysis and EPR results intuitive reveal the micro-morphology, band structure and active species of Ti³⁺ doped defective TiO₂. This work can provide an essential reference for structural regulation and composition of oxide semiconductor since the methodology could be freely applicable to other systems.