Visible light photocatalytic degradation of thiophene using Ag-TiO 2/multi-walled carbon nanotubes nanocomposite

Abstract

Ag-TiO2 nanocatalyst, supported on multi-walled carbon nanotubes, was synthesized successfully via a modified sol-gel method, and the prepared photocatalyst was used to remediate aqueous thiophene environmentally by photocatalytic oxidation under visible light. The prepared Ag-TiO 2/multi-walled carbon nanotubes nanocomposite photocatalyst was characterized through X-ray diffraction, Brunauer-Emmett-Teller (BET), transmission electron microscopy, and UV-vis spectra (UV-vis). The results showed that both Ag and TiO2 nanoparticles were well-dispersed over the MWCNTs and formed a uniform nanocomposite. Ag doping can eliminate the recombination of electron-hole pairs in the catalyst, and the presence of MWCNTs in the TiO2 composite can change surface properties to achieve sensitivity to visible light. The optimum mass ratio of MWCNT:TiO2:Ag was 0.02:1.0:0.05, which resulted in the photocatalyst's experimental performance in oxidizing about 100% of the thiophene in a 600 mg/L solution within 30 min and with 1.4 g L-1 amount of catalyst used. © 2013 Elsevier Ltd and Techna Group S.r.l.All rights reserved.