Characterization and photocatalytic activity of Eu:ZnO & Au/Eu:ZnO nanoparticles prepared by laser ablation in water

Herein we report on the photocatalytic activity of surfactant-free ZnO, Eu:ZnO, Au/ZnO, and Au/Eu:ZnO nanoparticles prepared by laser ablation of undoped and Eu-doped ZnO sintered targets and gold metal in distilled water. The hexagonal crystal structure of the ablated ZnO NPs was confirmed by the XRD analysis. The TEM images showed the formation of aggregated NPs with a nearly round shape and size in the range of 8-60 nm. The optical absorbance spectra indicated a slight widening of the bandgap energy in the Eu-doped ZnO NPs. The photoluminescence spectra of all samples displayed a sharp UV exciton emission of ZnO. The ablation yield was obviously enhanced in Eu-doped ZnO target compared to the undoped one, as revealed by the XRD, optical absorbance and PL spectra. The photocatalytic activity of the ablated NPs was evaluated by the decolorization of the R6G organic dye pollutant, under UV irradiation. The AU/Eu:ZnO NPs showed the highest photocatalytic efficiency of about 93% within 45 min. These results point out that laser ablation of Eu-doped sintered target and gold metal in distilled water can be an effective method to prepare ultra-pure Au/Eu:ZnO NPs with improved photocatalytic efficiency.