Enhanced photocatalytic activity of Fe-doped ZnO nanoparticles synthesized via a two-step sol-gel method

A series of Zn1-x Fe (x) O (x = 0, 1, 2, 3, 4 %) powders via a two-step sol-gel method in open system were successfully fabricated. Influence of Fe doping concentration on the structure, morphology, optical properties and photo catalysis properties were investigated by means of X-ray diffraction, scanning electron microscopy, UV-Vis spectrophotometer and photochemical reaction instrument. The results showed that the ZnO powders were hexagonal wurtzite structures and their crystalline sizes and particle diameters decreased with the increase of Fe doping concentration. An increase of visible light absorption value and a decrease in band gap from 3.219 to 3.167 eV were found with the increase of Fe doping concentration, which enable the sample harvest more photons to excite the electron from the valence. Enhanced visible light induced photocatalytic activity has been found in Fe doped ZnO and the ultraviolet light induced photocatalytic properties of the Fe-doped ZnO have been improved greatly compared with undoped ZnO and commercially available TiO2 (P25). The photocatalytic activities were not significantly affected by the particle size, and the best Fe doping concentration is 1 %.