title: Heterogeneous activation of H2O2 by defect-engineered TiO(2-x) single crystals for refractory pollutants degradation: A Fenton-like mechanism.
abstract: The heterogeneous catalyst plays a key role in Fenton-like reaction for advanced oxidation of refractory pollutants in water treatment. Titanium dioxide (TiO2) is a typical semiconductor with high industrial importance due to its earth abundance, low cost and no toxicity. In this work, it is found that TiO2 can heterogeneously activate hydrogen peroxide (H2O2, E°=1.78 eV), a common chemical oxidant, to efficiently generate highly-powerful hydroxyl radical, OH (E(0)=2.80 eV), for advanced water treatment, when its crystal shape, exposed facet and oxygen-stoichiometry are finely tuned. The defect-engineered TiO2 single crystals exposed by high-energy {001} facets exhibited an excellent Fenton-like activity and stability for degrading typical refractory organic pollutants such as methyl orange and p-nitrophenol. Its defect-centered Fenton-like superiority is mainly attributed to the crystal oxygen-vacancy, single-crystalline structure and exposed polar {001} facet. Our findings could provide new chance to utilize TiO2 for Fenton-like technology, and develop novel heterogeneous catalyst for advanced water treatment.
authors.affiliation: Department of Municipal Engineering, Hefei University of Technology, Hefei 230009, China. Electronic address: ayzhang@hfut.edu.cn.
authors.forename: Ai-Yong
authors.initials: AY
authors.lastname: Zhang
authors.affiliation: Department of Municipal Engineering, Hefei University of Technology, Hefei 230009, China.
authors.forename: Tan
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Municipal Engineering, Hefei University of Technology, Hefei 230009, China.
authors.forename: Yuan-Yi
authors.initials: YY
authors.lastname: He
authors.affiliation: Department of Municipal Engineering, Hefei University of Technology, Hefei 230009, China.
authors.forename: Yu-Xuan
authors.initials: YX
authors.lastname: Mou
keywords: Fenton-like; High-energy facet; Oxygen-stoichiometry; Single crystal; TiO(2)