Facet Dependent Activity of Fe(III) Species Modified TiO<sub>2</sub> for Simulated Sunlight Driven Fenton-like Reactions
Yang Zhao, Xiaomei Liu, Biao Ma, Yang Li, Xiaobin Fan, Fengbao Zhang, Guoliang Zhang, Wenchao Peng
Abstract
TiO2 crystals with different exposed facets are synthesized and modified facilely by depositing Fe(III) species. With more (101) facets exposed, the photoactivity of Fe-TiO2 is obviously enhanced with peroxymonosulfate (PMS) as oxidant. The degradation rate for 20 ppm Bisphenol A (BPA) on Fe-TiO2 (101) can achieve 0.219 min–1, ∼8.5 times faster than that of pure TiO2 under simulated sunlight irradiation. Photoelectrochemical measurements and density functional theory (DFT) calculations confirm that the interfacial charge transfer (IFCT) on Fe-TiO2 (101) is stronger than that on Fe-TiO2 (001) and a faster Fe(III)/Fe(II) transformation rate can be therefore achieved. As a result, the generation of ·OH and 1O2 will be accelerated with more (101) facets exposed, thus obtaining better photoactivity. Under the Fe-TiO2/PMS/Light system, BPA can be effectively degraded in a wide pH range or in the presence of multiple inorganic anions. After five cycles, 100% BPA can still be degraded within 60 min. The study provides new photocatalysts design strategy based on Fe(III)/Fe(II) redox for PMS based photocatalytic oxidation.