Coral-like B-doped g-C3N4 with enhanced molecular dipole to boost photocatalysis-self-Fenton removal of persistent organic pollutants

Mengyang Jing; Hui Zhao; Liang Jian; Chengsi Pan; Yuming Dong; Yongfa Zhu

doi:10.1016/j.jhazmat.2023.131017

Coral-like B-doped g-C₃N₄ with enhanced molecular dipole to boost photocatalysis-self-Fenton removal of persistent organic pollutants

J Hazard Mater. 2023 May 5:449:131017. doi: 10.1016/j.jhazmat.2023.131017. Epub 2023 Feb 21.

Authors

Mengyang Jing¹, Hui Zhao¹, Liang Jian¹, Chengsi Pan¹, Yuming Dong², Yongfa Zhu³

Affiliations

¹ International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China.
² International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: dongym@jiangnan.edu.cn.
³ International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China; Department of Chemistry, Tsinghua University, Beijing 100084, China.

PMID: 36812729
DOI: 10.1016/j.jhazmat.2023.131017

Abstract

Fenton process is a popular advanced oxidation process for water purification. However, it requires an external addition of H₂O₂, thus raising safety threats and economic costs and encountering the problems of slow cycling of Fe²⁺/Fe³⁺ and low mineralization efficiency. Herein, we developed a novel photocatalysis-self-Fenton system based on coral-like B-doped g-C₃N₄ (Coral-B-CN) photocatalyst for 4-chlorophenol (4-CP) removal where H₂O₂ can be in situ generated by photocatalysis over Coral-B-CN, the cycling of Fe²⁺/Fe³⁺ was accelerated by photoelectrons, and the photoholes promoted 4-CP mineralization. Coral-B-CN was innovatively synthesized by hydrogen bond self-assembly followed by calcination. B heteroatom doping produced enhanced molecular dipole, while the morphological engineering exposed more active sites and optimized band structure. The effective combination of the two enhances charge separation and mass transfer between the phases, resulting in efficient in-situ H₂O₂ production, faster Fe²⁺/Fe³⁺ valence cycling and enhanced hole oxidation. Accordingly, nearly all 4-CP can be degraded during 50 min under the combined action of more ·OH and holes with stronger oxidation capacity. The mineralization rate of this system reached 70.3%, which is 2.6 and 4.9 times higher than that of Fenton process and photocatalysis, respectively. Besides, this system maintained excellent stability and can be applied in a broad range of pHs. The study would provide important insights into developing improved Fenton process with high performance for the removal of persistent organic pollutants.

Keywords: 4-CP removal; Coral-B-CN; Hydrogen bond self-assembly; Photocatalysis-self-Fenton.