Tailoring band gap of ZnO nanoparticles via Cu doping for improved photocatalytic activity

Abstract This paper reports the improvement in photocatalytic performance of ZnO by substitution of Cu with variable Cu concentration. ZnO and Cu 0.5%, 1.0% and 2.0% doped ZnO nanoparticles have been synthesized by sol gel combustion method. Before measuring photocatalytic property, we have confirmed the HCP structure, granular nanoparticles morphology of all samples with XRD and SEM analysis. Functional group have been ascertain by FTIR peak assignment. Small variation in structural parameter and ZnO stretching mode indicate substitution of Cu at ZnO site of ZnO nanostructure. The band gap engineering with variable Cu concentration successfully reduces the apparent band gap, which help to improve the photocatalytic performance of ZnO. The Rhodamine B dye degradation efficiency depend on Cu doping concertation and shows best result for Cu 2% doped ZnO nanoparticles.