Comparative study of metal oxides and phosphate modification with different mechanisms over g-C3N4 for visible-light photocatalytic degradation of metribuzin

• 作者: Rui Yan Amir Zada Lei Sun Zhi-Jun Li Zhi-Yuan Mu Shuang-Ying Chen Fan Yang Jian-Hui Sun Lin-Lu Bai Yang Qu Li-Qiang Jing
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: RARE METALS(Monthly)
• 页码范围: 155-165
• 页数: 11页
• 语种: 英文

摘要

In this work,a comparative study of three fre-quently employed modification techniques to g-C3N4 (CN)nanosheets for the photocatalytic degradation of metribuzin(MET) under visible-light irradiation has been carried out in detail.The modification methods were coupling TiO2 nanoparticles (TO) as electron acceptors,nano-sized Fe2O3(FO) to construct a Z-scheme nanocomposite,and phos-phate (HP) modification to promote O2 adsorption.The steady-state and transient-state surface photovoltage spec-tra and transient photoluminescence (PL) spectra con-firmed that all the three modification techniques enhanced the charge separation with prolonged lifetimes and pre-sented degradation activities in the order of TO/CN ＞ FO/CN ＞ HP/CN.The TO/CN nanocomposite showed the highest photocatalytic activity for MET degradation,with a sixfold higher rate than bulk CN.Liquid chromatography-tandem mass spectrometry and radical trapping experi-ments indicated that the increased activity was related to the synergetic effect of two radicals (·O2-and ·OH)involved in the photocatalytic degradation pathway,which was different from the ·OH radical-dominated pathway of bulk CN.This work reveals the importance of charge separation and the influence of the radical pathway and provides guidance for the design of high-efficiency pho-tocatalysts.