Application of TiO2–RuO2/Ti electrodes modified with WO3 in electro- and photoelectrochemical oxidation of Acid Orange 7 dye

• TiO2–RuO2/Ti electrodes modified with WO3 were applied in AO7 degradation.
• Electrochemical behaviour of the electrodes was tested using cyclic voltammetry.
• Dye photoelectrochemical degradation was carried out under UV and Vis irradiation.
• The best results were achieved at TiO2(91%)–RuO2(3%)–WO3(6%)/Ti electrode.
• TiO2–RuO2/Ti electrodes modified with WO3 can be applied under Vis irradiation.

TiO2–RuO2/Ti electrodes modified with WO3 were applied in electro- and photoelectrochemical degradation of a monoazo dye (Acid Orange 7) under UV and Vis irradiation. Their electrochemical behaviour was investigated by recording cyclic voltammetry curves in the dye and supporting electrolyte solution. The highest oxidation power was stated in the case of the tested electrodes with WO3 content of 3% and various contents of other oxides.Electrolytic degradation of the monoazo dye coupled with the photocatalytic process resulted in higher conversion of the dye. Application of Vis irradiation was also advantageous but the efficiency of the degradation was slightly lower than under UV irradiation. Taking into consideration not only decolouration but also mineralization of the dye solution, the application of the electrode with 6% content of WO3 and the content of TiO2 higher than 90% resulted in highest degradation of the dye solution. TiO2–RuO2/Ti electrodes modified with WO3 seems to be applicable not only under UV irradiation but also under Vis irradiation, e.g. sunlight or even room light lamps.