Photoinduced Terminal Fluorine and Ti 3+ in TiOF 2 /TiO 2 Heterostructure for Enhanced Charge Transfer

作者：Jie Hu, Yi Lu, Xiaolong Liu, Christoph Janiak, Wei Geng, Si-Ming Wu, Xiao-Fang Zhao, Liying Wang, Ge Tian, Yuexing Zhang, Bao‐Lian Su, Xiaoyu Yang · 发表于：CCS Chemistry · 年份：2020 · DOI：10.31635/ccschem.020.202000305 · 被引用次数：26 · 研究领域：Inorganic Fluorides and Related Compounds、Ga2O3 and related materials、Luminescence Properties of Advanced Materials

As an effective way to enhance the photo/electro-catalytic performance of titanium dioxide (TiO 2 ) is to explore the positive roles of doped fluorine sites in the fluorinated TiO 2 systems, which, currently still lacks the direct experimental evidence due to the complexity of the species involved. Herein, we have fabricated TiOF 2 /TiO 2 with interfacial bridging fluorine (Ti 2 –F) via a coherent phase transition through hydrothermal synthesis. Nuclear magnetic resonance and electron paramagnetic resonance characterization have provided strong evidence of the transformation of the doped fluorine from Ti 2 –F to Ti 1 –F and the subsequent generation of Ti 3+ at the interface of the TiOF 2 and TiO 2 under UV–visible (UV–vis) light irradiation. Density functional theory (DFT) calculations and photo/electrochemical measurements further confirmed the electron donor behavior of the Ti 3+ . The benefit is a significantly enhanced charge transfer efficiency in TiOF 2 /TiO 2 , which not only resulted in improved performances for the photodegradation of acetone being 5.5 times higher than the commercial TiO 2 but also supported high capacity for sodium-ion storage. Thus, the TiOF 2 /TiO 2 with Ti 2 –F provided a perfect structure to investigate the roles of fluorine sites in fluorinated TiO 2 systems and their interaction with material properties.