Defect-engineered TiO₂ Hollow Spiny Nanocubes for Phenol Degradation under Visible Light Irradiation

Herein, we mainly report a strategy for the facile synthesis of defect-engineered F-doped well-defined TiO2 hollow spiny nanocubes, constructed from NH₄TiOF₃ as precursor. The topological transformation of NH₄TiOF₃ mesocrystal is accompanied with fluorine anion releasing, which can be used as doping source to synthesize F-doped TiO₂. Our result shows that the introduction of oxygen vacancies (Vo's) and F dopant can be further achieved by a moderate photoreduction process. The as prepared sample is beneficial to improve photocatalystic degradation and Photoelectrochemical (PEC) efficiency under visible light irradiation. And this improvement in photocatalytic and photoelectrocatalytic performance can be ascribed to the significant enhancement of visible light absorption and separation of excited charges resulted from the presence of oxygen vacancies, F^- ions and hollow structure of TiO₂.