Fe2O3–AgBr nonwoven cloth with hierarchical nanostructures as efficient and easily recyclable macroscale photocatalysts

Abstract

A prerequisite for the development of photocatalytic application is to obtain efficient and easily recycled visible-light-driven (VLD) photocatalysts. Usually, nanosized photocatalysts exhibit excellent photocatalytic performances but cannot be easily recycled, and film-shaped nanostructured photocatalysts on substrates (or magnetic photocatalysts) can be easily recycled but have low surface area and/or high production cost. To solve this problem, herein we report on the design and preparation of nonwoven cloth based on semiconductor–semiconductor (Fe₂O₃–AgBr as the model) nanojunctions as efficient and easily recyclable macroscale photocatalysts with nanostructure. Fe₂O₃–AgBr nonwoven cloth has been prepared by a simple electrospinning–calcination method. Such macroscale cloth is free-standing and it consists of hierarchical pores with diameters of 600–750 nm and nanofibers with diameters of 150–350 nm. Furthermore, these nanofibers are constructed from Fe₂O₃ and AgBr nanoparticles with diameters of ∼60 nm. In addition, Fe₂O₃–AgBr nonwoven cloth has magnetic properties and a broadened visible-light photo-response range (400–750 nm). Under the irradiation of visible light, Fe₂O₃–AgBr nonwoven cloth exhibits higher photocatalytic activity than Fe₂O₃ nonwoven cloth and AgBr nonwoven cloth containing the same weight of visible-light-active component, for the degradation of rhodamine B (RhB) and parachlorophenol (4-CP). Higher photocatalytic activity of Fe₂O₃–AgBr nonwoven cloth should result from the synergic effects between Fe₂O₃ and AgBr due to the broadening photoabsorption and the energy level matching. Importantly, Fe₂O₃–AgBr nonwoven cloth can be easily transferred and/or recycled by the dipping/pulling method and/or external magnetic field, and it has excellent photocatalytic stability during recycling tests. Therefore, this work provides some insight into the design and development of novel, efficient and easily recyclable macroscale nonwoven cloths, for future practical photocatalytic application, for example, degrading organic pollutants in polluted rivers.