Synthesis of dye-sensitized TiO2/Ag doped nano-composites using UV photoreduction process for phenol degradation: A comparative study

Abstract

This study investigates a comparison between the photocatalytic action of two nanocomposites (TiO2 and TiO2(Ag) doped) on the degradation of phenol from water. The nanocomposites were synthesized by the UV photo-reduction process to get a silver metal loading of 0.25, 0.5, 0.75, and 1% (w/w). In addition to this, Eriochrome Cyanine Red (ECR) and Eosin Yellow (EY) both anionic dyes were used for sensitization of Ag-doped TiO2 photo-catalyst such as TiO2(Ag)ECR and TiO2(Ag)EY. The TiO2(Ag-1.0)EY photo-catalyst indicated higher absorbance compared to the TiO2(Ag-1.0)ECR in the 400–700 nm range (visible range). The degradation of phenol was tested by varying the pH, silver loading and catalyst dosage. The maximum degradation of phenol was 98% in 180 min at pH 7 in presence of 1% (w/w) silver loading with 0.5 gL-1 dosage of photo-catalyst TiO2(Ag-1.0)EY. At this condition, the reduction in the phenol concentration was noticed from 20 mg/L to 0.4 mg/L.