Confinement-Modulated Singlet-Oxygen Nanoreactors for Water Decontamination
Yichuan Wang, Jianfeng Zheng, Tianlin Zhou, Quanzhi Zhang, Menghan Feng, Shuo Zhang
Abstract
Water decontamination with singlet oxygen ( 1 O 2 ) has shown advantages over the traditional radical-based treatment processes, which are frequently inhibited by the background inorganic/organic substances and produce toxic byproducts. However, earlier reported treatment systems mostly suffer from side reactions against efficient and cost-effective production of 1 O 2, together with insufficient utilization of 1 O 2 limited by the extremely short diffusion length. To overcome the drawbacks, we here designed high-performance nanoreactors by modulating the MnO 2 phase to nanotube structures (with ∼5 nm diameter, termed “NT 5 ”). With nanoconfinement, our developed NT 5 directed efficient and almost 100% utilization of peroxymonosulfate (PMS) to produce 1 O 2 and achieved maximal kinetics on organic pollutant elimination. The mechanism study revealed that the geometric strain of NT 5 together with spatial confinement modulated the adsorption properties of PMS molecules and led to their transformation to 1 O 2 . To demonstrate the applicability of NT 5, we developed a reactive filter with a particulate catalyst (NT 5 grown on an alumina substrate) that can effectively and stably work in a broad range of contaminated scenarios (surface water, groundwater, municipal secondary effluent, and industrial wastewaters), due to the confined treatment together with the fouling-resistance nature. Our study may boost the deployment of nanomaterials with confined catalysis and their applications in practical water treatment scenarios.