Direct Z-scheme Fe2(MoO4)3/MoO3 heterojunction: Photo-Fenton reaction and mechanism comprehension

• Published in: Journal of alloys and compounds Vol. 873; p. 159830
• Main Authors: Zhu, Yufeng, Ma, Shouchun, Yang, Yang, Li, Jiaqi, Mei, Yuqing, Liu, Li, Yao, Tongjie, Wu, Jie
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.08.2021; Elsevier BV
• Subjects: Degradation; Electric fields; Fenton reaction; Heterojunctions; Hydrogen peroxide; Inner electric field; Oxidation; Oxidizing agents; Photo-Fenton reaction; Photocatalysis; Pollutants; Recyclability; Structural analysis; Synergistic effect; Work functions; Z-scheme; Fenton reaction; Z-scheme; Photo-Fenton reaction; Photocatalysis; Inner electric field
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.159830

•Formation mechanism of “brick-like” Fe2(MoO4)3/MoO3 heterojunction is investigated.•Inner electric field built at interface is beneficial for Z-scheme path of electron.•H2O2 acts as oxidant in Fenton reaction and e- scavenger in photocatalytic reaction.•k is 0.107 min−1 in photo-Fenton reaction, 170 times higher than photocatalysis.•1140% of extra efficiency is yielded by coupling Fenton reaction and photocatalysis. Fe2(MoO4)3/MoO3 heterojunction was prepared by a grinding-calcination method, and they displayed rapid degradation performance in photo-Fenton reaction. [Display omitted] The photo-Fenton reaction consisted of photocatalytic reaction and heterogeneous Fenton reaction is an effective technique for pollutant degradation, because the degradation rate is faster than individual reactions. In this work, Fe2(MoO4)3/MoO3 heterojunction was prepared via a grinding-calcination method. Work function measurement indicated that the inner electric field was build at the interface between Fe2(MoO4)3 and MoO3, leading to a Z-scheme electron (e-) transfer pathway, and this result was supported by the radical quenching experiment and band structure analysis. In photo-Fenton reaction, the degradation rate was 57 and 170 times higher than those in heterogeneous Fenton reaction and photocatalytic reaction, respectively. This improvement was because H2O2 not only served as an oxidant in heterogeneous Fenton reaction, but also acted as scavenger of e- in photocatalytic reaction. Synergistic effect was established between heterogeneous Fenton reaction and Z-scheme photocatalytic process via H2O2 as a medium, and 1140% extra degradation efficiency was yielded by coupling these two reactions together. Besides high activity, 92.6% of degradation efficiency was remained after the 5th cycle, indicating an outstanding recyclability.