Effect on electrochemistry of hexacyanoferrate at carbon fibers after pretreatment with titanium chloride

A simple and fast method for carbon fiber activation is proposed to improve the electrochemical activity of electrodes made of carbon fibers. A layer of titanium (IV) oxide was coated on the carbon fiber surface, using titanium tetrachloride dissolved in carbon tetrachloride. The fibers were treated for 1 h at room temperature followed by hydrolyzation of the remaining chloride and finally dried. The electrochemical activity was evaluated by means of cyclic voltammetry. The titanium oxide layer dispersed onto the fiber surface was very stable and a large improvement in the electrochemical response was observed. The electrochemical response obtained for hexacyanoferrate was similar to that observed for reversible systems. The reproducibility of the proposed method was very good and no significant change in the electrochemical response was observed between equally prepared carbon fibers. (C) 1998 Elsevier Science S.A. All rights reserved.45741671838