A Novel Bifunctional Organic Supported Nano-Titania Photocatalyst via the Sol-Gel Method Using Walnut-Shell

Abstract

Nano-structured photocatalytic titania was prepared via the sol-gel method on the surface of carbon-rich organic support in situ to be used as a supported photocatalyst. The preparation process was lean, including sol preparation, mixing and calcination (450 degrees C). The microstructure and crystallinity were characterized by using SEM and XRD analysis. The prepared photocatalytic material shows better water clarification (dye removal) efficiencies than commercial nano titania, either excited by UV or visible light, or kept in the darkness. A bifunctional composite having both photocatalysis and adsorption capabilities simultaneously was prepared using walnut shell (WNS) as organic support for the first time. It has considerably higher dye removal rates (kapp values (min(-1))) when compared with commercial nano titania: 0.1827 (2.83 times higher), 0.1188 (9.35 times higher) and 0.1066 (12.25 times higher) under UV light, under visible light, and in the darkness, respectively, making it a promising candidate for water clarification processes.