Laser irradiance and wavelength-dependent compositional evolution of inorganic ZnO and ZnOOH/organic SDS nanocomposite material

Laser irradiance and wavelength-dependence controlling in the composition of ZnO-ZnOOH composite nanoparticles in sodium dodacyl sulfate (SDS) matrix is presented. Varying the energy of the laser and its wavelength used for ablation, the ratio of ZnO to ZnOOH, their particle sizes, and distributions can be widely controlled. Second and third harmonics of pulsed Nd:YAG laser is used to ablate a zinc target placed in aqueous media of SDS, with varying energies and simultaneous flow of pure oxygen in the closed vicinity of the laser-ablated plasma plume. A colloidal solution produced shows two UV-visible absorption peaks at 365 and 490 nm. The ratio of absorbance peaks at 365 and 490 nm decreases with an increase in energy, but the decreasing rate of their ratios is higher for the third harmonic compared to that of the second. XRD UV-visible absorption, transmission electron microscopy, and FTIR spectroscopic techniques are used for the characterization of the produced colloidal solution. A possible mechanism of the synthesis of ZnO and ZnOOH nanoparticles is proposed.