Photocatalytic degradation of methylene blue under visible light by dye sensitized titania

Abstract

The use of textile dyes remain relevant in the issue of water pollution. With the potential harm it may possess on the local flora and fauna, various methods of dye removal have been researched and employed, including photocatalytic degradation. TiO2, being a suitable semiconductor for this purpose needs to be sensitized prior to use, either by doping or chemical adsorption in order to activate in visible light. In this study, various natural dyes were employed to sensitize TiO2. It was found that chlorophyll was superior in dye degradation, with about a 60% reduction in dye concentration over a target 2 h, greater than that of the synthetic sensitizer N-719. This places chlorophyll based photocatalytic reactors as a potential tool for organic pollutant degradation which are also easy to manufacture and abundant in nature.