Photoelectrochemical performance of Ag nanoparticles on TiO2 films prepared by aerosol pyrolysis

Titanium dioxide (TiO2) layers were prepared by the pyrolysis of an ethanolic solution of di-iso-propoxy-titanium bis(acetylacetonate) in aerosol form, and then electrodeposited with Ag nanoparticles on their surface. The morphology and photoelectrochemical properties of the resulting Ag nanoparticles (NPs) on TiO2 films were found to be significantly tuned by varying the electrodeposition time in an aqueous electrolyte containing AgNO3 and KNO3. Photocurrent density-voltage curves and electrochemical impedance spectra revealed that the Ag NPs remarkably improved the short-circuit current density and open circuit voltage, and considerably reduced the electrochemical impedance. Therefore, Ag NPs deposition enhanced the photo-absorption of the TiO2 layer, excited photoelectrons by localised surface plasmon resonance, promoted photo-induced charge separation, and prevented electron-hole recombination.