Electrochemical synthesis of ZnO-WO3 nanocomposites and their photocatalytic activity

Heterometal oxide nanoparticles of ZnO-WO3 (ZWO) were synthesized using a facile dual step hybrid electrochemical-thermal technique. The role of surfactant additives during synthesis was investigated by introducing three different surfactants:Cetyltrimethyl ammonium bromide (Cetrimide), sodium dodecyl sulphate (SDS), and polyethylene glycol (PEG) into the electrolytic bath. X-ray diffraction and surface morphology studies indicate that the nanoparticles are cubic with an average crystallite size of 30-40 nm. Photocatalytic behaviour of these nanomaterials was tested using Methylene Blue (MB) and Eriochrome Black-T (EBT) as sample pollutants. The best results were observed for the photocatalyst generated in the presence of SDS as an additive and calcined at 650 C-omicron. High degree of decolourisation of both dyes resulting in complete mineralisation is due to the photocatalytic activity of ZWO which is greater than that of commercially obtained TiO2-P25 photocatalysts. This proves that the electrochemical synthetic route with its low cost and high efficiency is an excellent technique for the bulk synthesis of heterometal oxide photocatalysts which could effectively be used in effluent water treatment. [GRAPHICS] .