Visible-light-driven photo-Fenton reaction with α-Fe2O3/BiOI at near neutral pH: Boosted photogenerated charge separation, optimum operating parameters and mechanism insight

Jingjing Jiang; Jiaying Gao; Tianren Li; Yifan Chen; Qiannan Wu; Tengfeng Xie; Yanhong Lin; Shuangshi Dong

doi:10.1016/j.jcis.2019.07.038

Visible-light-driven photo-Fenton reaction with α-Fe₂O₃/BiOI at near neutral pH: Boosted photogenerated charge separation, optimum operating parameters and mechanism insight

J Colloid Interface Sci. 2019 Oct 15:554:531-543. doi: 10.1016/j.jcis.2019.07.038. Epub 2019 Jul 15.

Authors

Jingjing Jiang¹, Jiaying Gao¹, Tianren Li¹, Yifan Chen², Qiannan Wu², Tengfeng Xie², Yanhong Lin², Shuangshi Dong³

Affiliations

¹ Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, Jilin, China.
² College of Chemistry, Jilin University, Changchun 130012, Jilin, China.
³ Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, Jilin, China. Electronic address: dongshuangshi@gmail.com.

PMID: 31326785
DOI: 10.1016/j.jcis.2019.07.038

Abstract

The performance of the Photo-Fenton process is still limited by the low conversion rate of Fe³⁺/Fe²⁺ under near neutral conditions. We report a α-Fe₂O₃/BiOI catalyst that enhanced the efficiency of Fe²⁺ generation. The structure, morphology, chemical composition and chemical states of the catalyst were characterized. The α-Fe₂O₃/BiOI catalyst exhibited remarkable degradation performance for methyl orange (MO), phenol and tetracycline hydrochloride (TCH). The degradation efficiency of α-Fe₂O₃/BiOI with an optimum α-Fe₂O₃ loading was 3 and 10 times higher than those of pristine BiOI and α-Fe₂O₃, respectively. The excellent degradation performance arose from the synergistic effect of the efficient separation and transfer of photogenerated charge at the α-Fe₂O₃/BiOI solid-solid interface and the optimized Fenton reaction at the solid-liquid interface. The effects of operating parameters including the H₂O₂ concentration, solution pH, catalyst concentration and MO concentration on the degradation efficiency were investigated. Electron spin resonance results and reactive oxidation species scavenger experiments indicated that superoxide radicals could be transferred into hydroxide radicals via the activation of H₂O₂. A possible degradation pathway of TCH is proposed. This strategy provides a new perspective for improving the cyclic ability of Fe³⁺/Fe²⁺ over heterogeneous catalysts.

Keywords: Fe(3+)/Fe(2+); Mechanism; Photo-Fenton; Solid-liquid interface; Solid-solid interface.