Zn0.94Cd0.06O nanoparticles with various structures, morphologies and optical properties toward MB optodecolorization

Abstract

ZnO and Zn0.94Cd0.06O nanoparticles were synthesized by a sol–gel method at different calcination temperatures of 600, 700 and 800°C. Effect of calcination temperature on structural, morphological and optical properties of Zn0.94Cd0.06O nanoparticles was investigated by FT-IR, SEM, EDAX, XRD techniques, UV–vis absorption and photoluminescence (PL) spectroscopy. SEM micrographs showed that increase in the calcination temperature cause to change in the morphplogy of Zn0.94Cd0.06O nanoparticles from spherical at 600°C to rod-shaped particles at 800°C. XRD analysis data revealed that ZnO and Zn0.94Cd0.06O nanoparticles were crystallized in wurtzite phase. The average diameter of the synthesized nanoparticles calculated by Debbye–Scherrer formula was 29nm for ZnO and 24, 130 and 210nm for Zn0.94Cd0.06O nanoparticles calcined at 600, 700 and 800°C, respectively. UV–vis absorption and PL spectra indicated that there is a red-shift in the band-gap of Zn0.94Cd0.06O nanoparticles from 3.28eV to 3.08eV in comparison with that of pure ZnO nanoparticles and the red-shift value decreases with increase in the calcination temperature. All synthesized materials were also examined for their photocatalytic activity in decolorization of methylene blue (MB). The comparative results suggested high efficiency of Zn0.94Cd0.06O nanoparticles calcined at 600°C toward MB decolorization.