ZnO decorated polydimethylsiloxane sponges as photocatalysts for effective removal of methylene blue dye

Abstract

In this study, porous zinc oxide/polydimethylsiloxane (ZnO/PDMS) sponge-like photocatalysts were prepared by an eco-friendly sugar templating method. The ZnO particles were incorporated on the surface of the PDMS during the infiltration of PDMS solution into sugar template in the vacuum chamber and the porous structure was created during the leaching out of sugar particles in water. The as-prepared composite sponges were utilized as efficient photocatalysts for the effective removal of methylene blue dye from wastewater under visible, UV and UV–visible light. The photocatalytic efficiencies under UV–visible and visible light illumination were obtained ~93% and ~85% by the composite ZnO/PDMS with about 2.7- and 5.7-fold higher kinetics, respectively than the pure PDMS sponge. Importantly, a quicker kinetic reaction rate can be achieved by the composite sponges than pure sponge under UV light compared to other lights. Finally, the high recyclability demonstrates the potential applications of the PDMS based photocatalytic porous sponges for the mitigation of environmental issues.