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 photoelectrocatalytic 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 photocurrents and the highest photoelectrocatalytic activity were both obtained with electrodes prepared by heating, at 600 °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.