Abstract
The redox reaction between TiCl 3 and NaNO 3 to form Ti(IV) and NO 2 - prior to deposition in a specially designed TiCl 3 + NaNO 3 solution is the key step effectively promoting the cathodic deposition of porous TiO 2 films. The continuous reduction of NO 2 - to N 2 and NH 3 generates extensive OH - , enhancing the deposition rate of TiO 2 . The linear sweep voltammetric (LSV) and electrochemical quartz crystal microbalance (EQCM) studies reveal the electrocatalytic effect of oxy-hydroxyl-titanium already deposited onto the substrate for the NO 2 - and N 2 reduction. The porous and crystalline structures of as-deposited and annealed TiO 2 films are examined by field-emission scanning electron microscopic (FE-SEM), transmission electron microscopic (TEM) and selected area electron diffraction (SAED) analyses. © 2008 Elsevier B.V. All rights reserved.