Visible light photocatalytic degradation of cyanide using Au-TiO2/multi-walled carbon nanotube nanocomposites

Au-TiO2 nanocatalyst-supported multi-walled carbon nanotubes were effectively prepared by the sol-gel modified technique. The Au-TiO2/MWCNT nanocomposite was used to remove cyanide by photocatalytic oxidation under visible light irradiation. The Au-TiO2/MWCNT nanocomposite photocatalyst was characterized by XRD, TEM, UV-vis, and BET techniques. Results revealed the nanoparticles TiO2 and Au were well dispersed into MWCNT. Addition of Au and MWCNT can eliminate recombination pairs of electron holes in the Au-TiO2/MWCNT nanocomposite. Also, the presence of the MWCNT in the Au-TiO2/MWCNT nanocomposite transfers absorption of TiO2 from the UV region to visible region of the spectrum. The optimum weight ratio of MWCNTs:TiO2:Au was 0.06:1.0:0.10, which resulted in experimental performance photocatalyst oxidation of about 100% of the cyanide in a solution of 100 mg/L over 40 min, with 1.2 g/L of catalyst used. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.