Influence of Laser wavelength on morphological and optical properties of ZnO nanoparticles prepared by laser ablation in water

Nanoparticles (NPs) of Zinc oxide (ZnO) were prepared utilizing pulsed laser ablation of a Zinc metal plate in deionized water without utilizing surfactant. The effect of Laser wavelength on the characterization of ZnO was investigated. The 1064-nm and 532-nm wavelength beams produced from a Q-switched Nd: YAG laser at 10 ns pulse duration were employed. The SEM images displayed that the average diameter of the Zinc oxide NPs generated by the laser wavelength 532-nm are larger than the 1064-nm laser wavelength nanoparticles. Various sizes were observed of round ZnO nanoparticles in the SEM image. As the laser wavelength increased, the density of the nanoparticles in water increased. UV–vis analyses revealed that the absorption peak located at 342 nm (1064nm) and 344 nm (532nm). The nanoparticles formed at 1064 nm exhibited higher absorbance than the nanoparticles formed at 532 nm. The optical band gap is considered to be 3.42 eV for 1064 nm and 3.4 eV for 532 nm. (paper)