Photocatalytic performance of ZnO carbon composites for the degradation of methyl orange dye

Abstract

High yield, low cost, environmentally friendly chemical bath synthesis process is used to produce submicron structures of ZnO and ZnO-carbon composites. Synthesis of ZnO rod structures (submicron sized) were confirmed using SEM images. To synthesis ZnO-carbon composites, well characterized carbon spheres produced using aerosol assisted CVD technique was used. Use of carbon spheres as a seed during synthesis of ZnO is observed to produce multipod structures of ZnO on to the surface of carbon spheres; the growth is explained by proposing suitable model. Room temperature photoluminescence spectra recorded for ZnO and ZnO-carbon composites synthesized show a systematic disappearance of a band-edge emission (sharp peak present at ∼380 nm observed for pure ZnO) with increased number of carbon spheres. Competent photo-catalytic activity of synthesized composite is confirmed by studying photo degradation investigation performed using a model dye molecule i.e. methyl orange. The work reveals possibility to use synthesized composites as a nontoxic and biocompatible catalyst for fragmentation of a methyl orange dye molecule. Photo-degradation mechanism of a methyl orange dye is proposed herewith considering the role of carbon spheres and ZnO in presence of UV photon.