Enhanced photocatalytic activity of Fe doped ZnO nanocrystals under sunlight irradiation

Iron (Fe) doped ZnO nanocrystals (NCs) were synthesized by sol-gel method and characterized by X-ray diffraction (XRD), Raman spectroscopy, UV-vis diffuses reflectance spectroscopy and photoluminescence (PL). XRD analysis demonstrates that all prepared samples present pure hexagonal wurtzite structure. The nanocrystals size was found to decrease with Fe doping concentration. The strain does not change monotonically and takes its maximum value for doping 3% Fe. Raman study indicates the good crystallinity of all ZnO samples with apparition of new peaks relative of amorphous Fe2O3 phases. UV-visible measurements show a reduction in band gap of NCs with increase in Fe content. PL spectra evidence formation of FeZn-VZn complexes for 3% Fe doping. ZnO: Fe NCs were found to be good photocatalyst for sunlight degradation of Rhodamine B (RhB). The photocatalytic activity is optimized to Fe doping concentration of 3%.