ZnO and ε-Zn(OH)2 Composite Nanoparticles by Pulsed Laser Ablation on Zn in Water

Wurtzite-type (W)-ZnO and ε-Zn(OH)2 composite nanoparticles following a specific crystallographic relationship (0001)W//(010)ε; [112̅0]W//[100]ε were fabricated by pulsed laser ablation on a Zn target in water and then characterized by analytical electron microscopy. The composite nanoparticles are platy and equiaxed in shape when fabricated by a peak power density of 1.7 × 1011 W/cm2 (1064 nm excitation) and 8.3 × 1010 W/cm2 (532 nm excitation), respectively. The W-ZnO nanoplates showed well-developed (0001) terraces for mutual coalescence and {101̅0} and {112̅0} edges for lateral growth. The W-ZnO and ε-Zn(OH)2 composite nanocondensates have an internal compressive stress up to ca. 0.7 GPa and a minimum band gap of ∼3.1 eV for potential optoelectronic applications in water environment.