Accelerated Fe(Iii)/Fe(Ii) Cycle Couples with In-Situ Generated H2o2 Boosting Visible Light-Induced Fenton-Like Oxidation

Abstract

Conventional Fenton process operated along with high economic cost due to the requirement of highly acidic pH and an enormous addition of H 2 O 2 . And the low conversion rate of Fe(III)/Fe(II) may lead to decline of oxidation performance during the process. Here, we constructed a visible light-induced heterogeneous Fenton-like process on a novel Fenton-like catalyst which consisted of immobilized Fe(III)-TiO 2  microspheres as Fenton-like reagent and g-C 3 N 4 -porphyrin lamella as in-situ H 2 O 2  donor. The immobilized Fe species showed good stability and reduced the loss of Fe during Fenton-like process. Meanwhile, taking advantage of interfacial charge transfer (IFCT) effect among Fe(III)-TiO 2  microspheres, the transformation from Fe(III) to Fe(II) was accelerated by photo-induced electrons from conduction band of the microspheres. And the π–π interaction between porphyrin and g-C 3 N 4  also strikingly promoted the in-situ H 2 O 2  production, which also boosted the Fenton-like process along with the IFCT effect. Stronger electron spin resonance signal of •OH confirmed the boost mentioned above and indicated that g-C 3 N 4 -porphyrin provided H 2 O 2  in abundance for the Fenton-like process. This new Fenton-like catalyst exhibited superior oxidation performance and the optimum catalyst TFMS-CP0.1 achieved the removal of 92.6 % and 84.6 % towards phenol and hydroquinone in 3 hours, respectively, and 88.2 % towards MO in 1 hour. This work proposed a credible mechanism of visible light-induced Fenton-like process and achieved efficient oxidative degradation of the organic contaminant.

Keywords: Fenton-like process, oxidation performance, interfacial charge transfer effect, in-situ generated H2O2