Surface modification and immobilization in poly(acrylic acid) of Ag/ZnO for photocatalytic degradation of endocrine-disrupting compounds

Silver-modified ZnO particles (Ag/ZnO) are effective catalysts for the photodegradation of water pollutants such as bisphenol-A. However, until now, their use in continuous processes was back-drawn because of difficulties associated with their recovery. To overcome this problem, the present work aimed at immobilizing Ag/ZnO in cross-linked poly(acrylic acid) -PAA-. Ag/ZnO was first silanized using (3-glycidyloxypropyl)trimethoxysilane and thoroughly dispersed in a water-acrylic acid solution. The suspension was then submitted to radical polymerization in presence of a cross-linker (N,N′-Methylenebisacrylamide). The resulting composites were characterized in terms of chemical structure, morphology, crystallinity, thermal properties, and photostability. Their analyses showed that the silanized particles were chemically anchored to PAA and homogeneously distributed in the matrix. UV-assisted photocatalysis of bisphenol-A aqueous solutions showed that immobilized Ag/ZnO can achieve photodegradation performances comparable to pure Ag/ZnO and allows its use in successive cycles and, consequently, in continuous processes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43528.