Preparation and characterization of Ni, Co doped ZnO nanoparticles for photocatalytic applications

Abstract Ni, Co codoped ZnO nanoparticles have been synthesized by co-precipitation method. The structural and morphological properties of Ni, Co codoped ZnO nanoparticles were analyzed using X-ray diffraction, scanning/transmission electron microscopy and Energy-dispersive X-ray spectroscopy (EDX). Photoluminescence studies were also performed. PL spectra show a shift in near band edge (NBE) UV emission from 321 to 322 nm and a shift in red band (RB) emission from 620 to 631 nm which conforms the substitution of Ni into the ZnO lattice. XRD data revealed that Ni, Co codoped ZnO nanoparticles presented pure wurtzite phase. Their photocatalytic activity was investigated by the degradation of Rhodamine B (RhB) dye under visible light irradiation and compared with pure ZnO activity. The improved photocatalytic activity in degradation of rhodamine B (RhB) was observed at ∼0.2% at of both Ni and Co dopants. It seems that increasing doping concentrations of Ni, Co leads to a decrease of the photocatalytic efficiency. Further studies will target fine tuning of Ni and Co concentrations around the one with observed maximum activity and integration of the respective powder in a sensing system in order to verify also sensing ability of the material with best photocatalytic activity.