New TiO2/C sol-gel electrodes for photoelectrocatalytic degradation of sodium oxalate

This paper reports the preparation of carbon doped TiO2 electrodes by a modification of a sol-gel route. The electrodes have been characterized by measuring their photocurrent, as a function of applied potential. Their photoelec-trocatalytic activity, relative to similar sol-gel electrodes without carbon, has been assessed by measuring the decomposition of a 10 mM sodium oxalate solution. Measurements have been made on electrodes prepared with 2%, 5% and 10% of active carbon. The highest photo-currents and the highest photoelectrocatalytic activity were both obtained with electrodes prepared by heating, at 600 degrees C, electrodes prepared with 5% of active carbon. All the electrodes showed evidence of enhanced photocatalytic activity at 1.2 V. Five percent addition of C double the measured rates of photodegradation, even though, in these preliminary studies, no attempt has been made to optimize the type of carbon or the details of the electrode preparation. (c) 2005 Elsevier Ltd. All rights reserved.