Xiao Qian, Li Wanbin, Xie Shujie, Wang Li, Tang Chuyang Y
Department of Civil Engineering, The University of Hong Kong, Hong Kong, SAR 999077, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Nat Commun. 2024 Nov 7;15(1):9607. doi: 10.1038/s41467-024-54055-x.
Chlorinated organic pollutants widely exist in aquatic environments and threaten human health. Catalytic approaches are proposed for their elimination, but sluggish degradation, incomplete dechlorination, and catalyst recovery remain extremely challenging. Here we show efficient dechlorination using ferrous oxide/graphene oxide catalytic membranes with strong nanoconfinement effects. Catalytic membranes are constructed by graphene oxide nanosheets with integrated ultrafine and monodisperse sub-5 nm nanoparticles through simple in-situ growth and filtration assembly. Density function theory simulation reveals that nanoconfinement effects remarkably reduce energy barriers of rate-limiting steps for iron (III)-sulfite complex dissociation to sulfite radicals and dichloroacetic acid degradation to monochloroacetic acid. Combining with nanoconfinement effects of enhancing reactants accessibility to catalysts and increasing catalyst-to-reactant ratios, the membrane achieves ultrafast and complete dechlorination of 180 µg L dichloroacetic acid to chloride, with nearly 100% reduction efficiency within a record-breaking 3.9 ms, accompanied by six to seven orders of magnitude greater first-order rate constant of 51,000 min than current catalysis. Meanwhile, the membranes exhibit quadrupled permeance of 48.6 L m h bar as GO ones, because nanoparticles adjust membrane structure, chemical composition, and interlayer space. Moreover, the membranes show excellent stability over 20 cycles and universality for chlorinated organic pollutants at environmental concentrations.
氯化有机污染物广泛存在于水生环境中，威胁着人类健康。人们提出了催化方法来消除这些污染物，但降解缓慢、脱氯不完全以及催化剂回收仍然极具挑战性。在此，我们展示了使用具有强纳米限域效应的氧化亚铁/氧化石墨烯催化膜进行高效脱氯。催化膜由氧化石墨烯纳米片构建而成，通过简单的原位生长和过滤组装集成了直径小于5纳米的超细微且单分散的纳米颗粒。密度泛函理论模拟表明，纳米限域效应显著降低了亚硫酸铁络合物解离为亚硫酸根自由基以及二氯乙酸降解为一氯乙酸的限速步骤的能垒。结合增强反应物与催化剂接触以及提高催化剂与反应物比例的纳米限域效应，该膜实现了将180微克/升的二氯乙酸超快速且完全脱氯为氯离子，在破纪录的3.9毫秒内还原效率接近100%，同时一级速率常数比当前催化反应高出六到七个数量级，达到51,000分钟。此外，由于纳米颗粒调整了膜的结构、化学成分和层间间距，该膜的渗透通量是氧化石墨烯膜的四倍，达到48.6升·平方米·小时·巴。而且，该膜在20个循环中表现出优异的稳定性，对环境浓度下的氯化有机污染物具有通用性。
