Mesoporous WO3/TiO2 spheres with tailored surface properties for concurrent solar photocatalysis and membrane filtration. (January 2021)

• Record Type: Journal Article
• Authors: Zhao, Ting; Qian, Ruifeng; Zhou, Guanda; Wang, Yu; Lee, Wan In; Pan, Jia Hong
• Is Part Of: Chemosphere. Volume 263(2021)
• Publication Date: 2021-01
• Subjects: Semiconductor photocatalysis -- Dye degradation -- Advanced oxidation process -- Self-assembly -- Monodisperse spheres -- TiO2 -- Membrane filtration; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128344
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The strategical integration of membrane water filtration with semiconductor photocatalysis presents a frontier in deep purification with a self-cleaning capability. However, the membrane fouling caused by the cake layer of the reclaimed TiO2 nanoparticles is a key obstacle. Herein, mesoporous WO3 /TiO2 spheres (∼450 nm in diameter) consisting of numerous self-assembled WO3 -decoated anatase TiO2 nanocrystallites are successfully prepared via a facile wet-chemistry route. The decoration of monolayered WO3 significantly affects the surface, photocatalytic, and optical properties of original mesoporous TiO2 spheres. XRD and Raman analyses show the presence of monolayered WO3 suppresses the crystal growth of TiO2 during the calcination process, significantly improves the surface acidity, and causes an obvious red shift in absorption edge. These favorable textural properties, coupling the enhanced interfacial charge carrier separation, render mesoporous WO3 /TiO2 spheres with a superior photocatalytic activity in degradation of methylene blue under UV, visible, and solar light irradiations. The optimal molar ratio of W/Ti is examined to 6%. The synthesized mesoporous WO3 /TiO2 spheres also show much higher flux during membrane filtration in both dead-end and cross-flow modes, suggesting a promising photocatalyst for concurrent membrane filtration and solar photocatalysis. Graphical abstract: Image 1 Highlights: Mesoporous WO3 /TiO2 spheres (TW- x ) are synthesized by incipient-wetness impregnation of self-template. Efficient charge carrier separation and surface acidity improve the UV and visible light photocatalytic activity of TW- x. Reclaiming of TW- x can be readily achieved by membrane filtration with high flux retention.