Photocatalytic coatings of silver–TiO2 nanocomposites on foamed waste-glass prepared by sonochemical process

Silver–TiO2 nanocomposite was prepared by photodeposition of silver nanoparticles on the surface of titanium dioxide. The sonochemical method was used for the deposition of silver–TiO2 powder on commercial foamed waste-glass strips (FWGS). The silver–TiO2 and the coated FWGS was characterized by XRD, DRS, SEM, TEM and nitrogen adsorption. In order to enhance silver–TiO2 deposition, different parameters were evaluated such as the solvent effect and use of stabilizing agents. The best deposition was obtained with an aqueous solution of polyvinyl alcohol (PVA) and an ultrasound irradiation source of 23.3 kHz. The photocatalytic activity of the silver–TiO2 coated FWGS was evaluated in the UV photo-assisted destruction of the noxious microalgae, Tetraselmis suecica. It was found that after the photocatalytic irradiation, for 180 min, the algae cells were deformed, fragmented and annihilated, thereby avoiding its regeneration.

Silver–TiO2 nanocomposite coated on foamed waste glass displays excellent photocatalytic performance in the elimination of the noxious microalgae Tetraselmis suecica under UV-light irradiation. The synergy effect of silver nanoparticles and TiO2 help to fragment the cytoplasm and the silver biocide properties inhibit the growth of unicellular algae.Figure optionsDownload as PowerPoint slideHighlights
► The silver–TiO2 powder was deposited on commercially available foamed waste-glass by an ultrasound-assisted process.
► The best results of deposition are obtained in the presence of polyvinyl alcohol (PVA) which is used as a stabilizing agent and ultrasound irradiation at 23.3 kHz.
► The solvent effect on the deposition of the powder appears to be consistent with the dielectric constant of the solvents.
► Immobilized silver–TiO2 showed good photocatalytic elimination of the microalgae Tetraselmis suecica under UV-A irradiation.