Synthesis of visible light driven ZnO: Characterization and photocatalytic performance

Abstract

Nanocrystalline materials of pure and doped ZnO with La/Ce metals have been successfully synthesized using sol gel method. The prepared materials were characterized by standard analytical techniques, i.e., XRD, SEM, EDX, UV–vis Spectroscopy and FTIR. The (XRD) analysis showed that the obtained particles are present in partial crystalline nature with Hexagonal wurtzite phase and exhibit no other impurity phase. The EDX and (SEM) images depicted that La and Ce metals has been successfully loaded on the surface of ZnO. FTIR of La doped ZnO showed an additional absorption band at 910cm−1, characteristic of La–O absorption band indicating the incorporation of dopant into the ZnO lattice in addition to a broad and strong absorption band in the region of 410–580cm−1 due to Zn–O stretching. The UV–vis absorption spectra of synthesized particles indicate that the doping of La and Ce metals into the ZnO lattice shift the absorption band towards the visible region. Thermal analysis measurement of the synthesized sample showed that the thermal stability of pure ZnO is decreased due to increase in dopant concentration. The photocatalytic activity of the synthesized particles was studied by measuring the change in concentration of three different chromophoric dyes as a function of irradiation time. The photocatalytic activity of doped ZnO was found to increase with increase in dopant concentration of Ce from 0 to 2.0% and La from 0 to 0.9%. A further increase in dopant concentration led to decrease in the degradation rate of dyes.