氧掺杂氮化碳纳米片活化过二硫酸盐选择性去除酚类污染物的特性与机制OA北大核心CSTPCD
Performance and mechanism of selective degradation of phenolic pollutants by peroxydisulfate activated over oxygen doped graphic carbon nitride nanosheets
以富氧生物质单宁酸为氧源,通过热氧化剥离制备了氧掺杂石墨相氮化碳纳米片(O-CN),利用氧原子掺杂调控O-CN纳米片的表面电子结构,提升其活化过二硫酸盐(peroxydisulfuric acid,PDS)降解水中酚类污染物的性能,探究了氧掺杂导致的O-CN电子结构变化及其活化PDS降解酚类污染物的效能和机制.结果表明,氧掺杂通过取代氮化碳(g-C3N4)中的N原子,促使O-CN纳米片表面电荷重新分布,促进了 O-CN表面未配对电子的形成,进而显著增强了其PDS活化性能和酚类污染物的降解能力.在中性条件下,PDS与酚类污染物质量浓度摩尔比为1∶10时,0.1 g·L-1的O-CN纳米片活化PDS(0.4 mmol·L-1)可在60 min内将双酚A(bisphenol,BPA)、苯酚(phenol)、对乙酰氨基酚(acetaminophen,AAP)完全去除.电子顺磁共振(electron paramagnetic resonance,EPR)、化学淬灭及原位拉曼和电化学分析表明,O-CN/PDS体系主要通过电子转移的方式氧化去除酚类污染物,对无机阴离子等水体背景成分具有较强的抗干扰能力.O-CN纳米片具有良好的稳定性,可构建催化膜持续降解酚类污染物,在10 h的连续反应中可稳定去除全部BPA,且保持了较高的矿化效率(60%).
Oxygen doped graphic carbon nitride(O-CN)nanosheets was prepared via thermal exfoliation by using tannic acid as the oxygen source,aiming to tuning the surface electronic structures of carbon nitride and enhancing its performance toward the activation of peroxydisulfate(PDS)and degradation of phenolic pollutants.The variation of the electronic structure of O-CN nanosheets induced by oxygen doping was investigated.The performance and mechanism of PDS activation and phenolic pollutants degradation over O-CN was studied systematically.The results showed that oxygen doping mainly occurred on nitrogen positions,leading to redistribution of surface electrons and formation of unpaired electrons,which greatly enhanced the activation of PDS and degradation of phenolic pollutants.Under neutral conditions and the mole ratio of 1:10 for phenolic pollutants to PDS,phenolic pollutants(such as bis-phenol A,phenol and acetaminophen)could be completely removed by O-CN(0.1 g·L-1)within 60 min.The degradation of phenolic pollutants was mainly depended on electron transfer regime according to the electron paramagnetic resonance tests(EPR),chemical quenching experiments,in situ Raman analysis and electrochemical measurements.The nonradical oxidation pathway led to good anti-interference capability to complex surroundings like inorganic ions.The O-CN nanosheets showed a good stability and can be used to construct catalytic membrane for degrading phenolic pollutants continuously.Complete removal of bis-phenol A with a high mineralization efficiency(60%)occurred during 10 h of operation.
李丹阳;高悦莹;张哲睿;张佳乐;王震鑫;王根;杨生炯
西安建筑科技大学环境与市政工程学院,西安 710055||西北水资源与环境生态教育部重点实验室,西安 710055
环境科学
高级氧化氮化碳氧掺杂酚类污染物电子转移
advanced oxidation processgraphitic carbon nitrideoxygen dopingphenolic pollutantselectron transfer
《环境工程学报》 2024 (008)
2121-2131 / 11
陕西省自然科学基础研究计划(2024JC-YBMS-290)
评论