A new strategy to address the challenges of nanoparticles in practical water treatment: mesoporous nanocomposite beads via flash freezing. Issue 48 (29th November 2017)

• Record Type: Journal Article
• Authors: Pan, Siyuan; Zhang, Xiaolin; Qian, Jieshu; Lu, Zhenda; Hua, Ming; Cheng, Cheng; Pan, Bingcai
• Is Part Of: Nanoscale. Volume 9:Issue 48(2017)
• Page Start: 19154
• Page End: 19161
• Publication Date: 2017-11-29
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c7nr06980d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The well-dispersed NPs and their high reactivity make Fe2 O3 @PS quite attractive for water decontamination. Abstract : Various engineering nanoparticles (NPs) exhibit high reactivity and great potential for water decontamination. Encapsulation of NPs into millimeter-sized polymer hosts is a very promising strategy to address their inherent bottlenecks for scale-up water treatment such as aggregation, difficult operation and potential risks when released into water. However, the inevitable host pore blockage accompanying NP loadings significantly compromise their decontamination reactivity. Herein, a newly developed flash freezing method was utilized to embed α-Fe2 O3 NPs (3 nm, 7 nm and 18 × 90 nm) inside millimetric polystyrene to prepare mesoporous nanocomposites Fe2 O3 @PS. All the as-obtained Fe2 O3 @PS nanocomposites feature high mesoporosity, well-dispersed NPs and highly accessible sites. The amount of Fe–OH species, i.e., the active sites for As(v ) sequestration, of the embedded 3 nm-Fe2 O3 is dramatically increased 3.6 times over the bare NPs, resulting in higher adsorption capacity and affinity. The 3 nm-Fe2 O3 @PS is capable of producing clean water 2000-fold greater in mass successively in column adsorption, with As(v ) reducing from 176 μg L −1 initially to <1 μg L −1 . Also, Fe2 O3 @PS can be readily regenerated for cyclic use with negligible NPs leaking into water. This study provides an elaborate strategy to address the trade-off between easy operation and decontamination reactivity of NPs for water treatment.