Preparation of novel catalyst, titaniumdioxide/chitosan film and application as media in photocatalytic process for chromium (VI) removal

Abstract

In this research, TiO2/chitosan film was prepared by using tiO2 (Degussa P-25) and chitosan flake from crab shells dissolved in 20% acitic acid solution. From this study the preparation of TiO2/chitosan film in different composition of the chitosan and Ti contents were investigated to produce a composite TiO2/chitosan film. In this work, effects of chitosan ant Ti content on TiO2/chitosan film properties, adsorption and photocatalytic activity for chromium (IV) removal were investigated. The adsorption and photocatalytic activity of the composite material were tested by the reduction of chromium (VI) in aqueous solution. With ihe chelating ability of chitosan, the enhancing of photocatalysis using this synthesis composite material was observed. Results obtained from adsorption activity shown that the adsorption isotherm pattern of TiO2/chitosan film for chromium (IV) removal was followed the Langmuir adsorption isotherm model. For photocatalytic activity, using TiO2/chitosan film with the highest chitosan content (2.5% chitosan, 0.4% Ti) can provide the highest efficiency in removing of 100 mg/L chromium(VI). The appearance rate constant (0.0255 min-1) of TiO2/chitosan film was higher than that obtained from pure TiO2(0% chitosan, 0.4% Ti) (0.0003 min-1). While TiO2/chitosan film with the highest Ti content (0.8% Ti, 1.5% chitosan), provided higher appearance rate constant (0.0358 min-1) than that obtained from pure TiO2 powder. From this work the synthesized composit material, TiO2/Chitosan film can be a potential catalyst for heavy metal removal in further photocatalytic process.