No abstract

No abstract

No abstract

Nanostructured zinc oxide thin films, prepared by sol-gel, were subjected to surface loading of silver/gold nano-isles by controlled electrodeposition, using aqueous solutions (10 -2 M) of silver nitrate and chloroauric acid as precursor. The deposition potentials were, respectively, -400 and -200 mV for silver and gold depositions, as the deposition time varied from 5 to 60 s. Pristine samples (i.e., samples with no deposition of metal nano-isles) were also obtained for comparison. X-ray diffractometry indicated dominant evolution of wurtzite zinc oxide phase, with a possible diffusion of silver/gold into zinc oxide lattice. However, changes in the band gap energy were insignificant. Atomic force microscopic and scanning electron microscopic analyses revealed the surface topography and morphology. Energy-dispersive X-ray analysis confirmed the elemental stoichiometry and existence of silver and gold nanoparticles in films. Samples exhibited significant gain in photoelectrochemical water splitting current, which is largely attributable to the facilitative role played by silver/gold nano-isles in the separation and transport of photogenerated charge-carriers.

No abstract