Abstract
Cathodic deposition of titanium dioxide (TiO 2 ) from two plating solutions with H 2 O 2 and NaNO 3 as their respective oxidants for converting Ti(III) into Ti(IV) are systematically compared. From the electrochemical quartz crystal microbalance (EQCM) and mass loading studies, the deposition solution containing H 2 O 2 , denoted as bath A, exhibits a higher rate of TiO 2 deposition in comparison with the solution containing NaNO 3 , denoted as bath B, probably due to the formation of Ti(IV) oxy-hydroxyl species in bath A. However, the surface morphology and crystalline structure of annealed TiO 2 deposits are not significantly affected by using different deposition baths. TiO 2 deposits have been successfully electroplated onto Ti substrates from both baths under the dual-electrode deposition mode. The surface morphology of TiO 2 is significantly influenced by the deposition methods including galvanostatic, potentiostatic, and pulse-rest modes. Finally, uniform porous morphologies of TiO 2 in cm 2 scale are controllable by varying the pulse-rest deposition variables (e.g., pulse frequency and duty percentage) due to its unique advantages such as excellent adhesion, good uniformity, and controllable particle size of TiO 2 . © 2012 The Electrochemical Society.