Well-Supported Ag3VO4–AgBr Nanostructures for Visible Light-Driven Treatment of Wastewaters

Abstract

Ag3VO4–AgBr nanoparticles were loaded on fluorapatite (FA) and carboxymethyl cellulose (CMC) supports by an ionic liquid-mediated precipitation method and used as effective visible light-driven photocatalysts for the degradation of Acid Blue 92 (AB92) azo dye as a typical wastewater. The products were characterised by powder X-ray diffraction (XRD), diffuse reflectance spectroscopy, FTIR, scanning electron microscopy (SEM) and nitrogen adsorption–desorption isotherms using Brunauer–Emmett–Teller (BET) analysis. The XRD patterns confirmed the formation of Ag3VO4 and AgBr crystalline phases. Moreover, the SEM images indicated that the photoactive agents were homogeneously dispersed on the surface and the average size of the particles was between 45 and 95 nm. During the treatment time, the photogenerated electron–hole pairs reacted with the species in the solution and produced OH•, HO2• and O2•– species which attacked the organic pollutants and destroyed the crucial bonds. Recycling experiments confirmed that the CMC-based photocatalyst was more active during the first time of using while the FA analogue was determined to be sufficiently active after five cycles of usage.