Evaluation of the photo-electro-catalytic behavior of nano-structured ZnO films fabricated by electrodeposition process

Nanostructured ZnO thin films were synthesized on fluorinated tin oxide (FTO) substrate by electrodeposition process. The effect of applied voltage on the structure and photocatalytic behavior of the films was investigated. The deposition was conducted at different voltages of 0.5, 0.7, 0.9, and 1.1 V for 1000 s in an aqueous electrolyte containing both zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and sodium nitrate (NaNO3) at 70 °C. The morphology and elemental analysis of the ZnO films were investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. Photocatalytic behavior of the samples was evaluated by linear sweep voltammetry, amperometry, and electrochemical impedance tests under the ultraviolet light irradiation at a wavelength of 375 nm in a solution of sodium sulfate (Na2SO4). Results demonstrated that the film synthesized at 1.1 V showed the best photocatalytic behavior in comparison with the other samples.