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A systematic cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) study on titanium dioxide (TiO2) and silver–TiO2 surfaces was performed in order to decouple electrochemical reduction processes of carbon dioxide in aqueous solutions. CV studies indicate cathodic current increase on Ag–TiO2 compared to bare TiO2 surfaces. An equivalent circuit based on transmission line model was applied in order to adjust EIS data, and a modification of this model was made to account for Ag particle interaction with the electrolyte solution. Electrochemical processes were then decoupled upon applied potential where the role of TiO2 surface states was identified and separated from (a) silver reduction, (b) electronic transport on TiO2, and (c) charge transfer on TiO2 and Ag surfaces. The Ag–electrolyte interface impedance has considerably lower values than the TiO2–electrolyte interface, suggesting that the silver particles may be considered as favorable reaction sites for the electrochemical reduction of water and carbon dioxide.

TiO2 thin films supported on transparent conductive glass plates were modified by silver particles (250 nm diameter) deposited by electrochemical double pulse from an aqueous solution of silver nitrate. Selective formation of Ag particles on TiO2 surface could be seen from SEM and AFM images and topography. Rugosity and particle size analyses were performed on the modified surface. Benefits of silver particle modification are discussed based on the enhanced electrochemical reduction of carbon dioxide in aqueous solution.

Silver nanoparticles were deposited on titanium oxideIV (TiO2) thin films supported on FTO (fluorine-doped tin oxideIV) glass using a double pulse electrochemical deposition method. A systematic study of particle nucleation and growth is presented as a function of applied potential and time. Samples were analyzed by grazing-angle X-ray diffraction (GIXRD) technique and morphology was observed using Scanning Electron Microscopy and Energy Dispersive Spectroscopy device (SEM–EDS). Our results confirm the possibility of controlled electrochemical homogeneous deposition of metallic silver particles over TiO2 surface, which exhibit a potential application in catalytic processes.