Performance evaluation of rotating photoelectrocatalytic reactor for enhanced degradation of methylene blue

Abstract

Enhanced oxidation of organic pollutant, methylene blue (MB) was conducted using a newly designed rotating photoelectrocatalytic process (PECP), compared with photocatalysis. A significant synergy of photoelectrocatalytic reaction was observed such that the degradation of methylene blue (MB) by the photoelectrocatalytic mode was 80% higher than that (61.6%) of photocatalytic mode. To confirm the potentials in the application of water treatment, the effects of various parameters affecting reaction performance were studied with the newly designed rotating photoelectrocatalytic reactor consisting of TiO2 nanotubes and Ti lath as the photoanode and cathode, respectively, for applying electrical potential under UV irradiation. As the result of parameter studies, such as applied electrical potential (voltage), UV light intensity, rotating speeds, the highest degradation efficiencies of MB were achieved at 2.5 V or less (electrical potential), 90 rpm (rotating speed), and higher UV intensity. In addition, the stability and activity of TiO2 nanotubes electrode were studied through repeated experiments and showed a good performance, excellent stability, and reliability in the rotating photoelectrocatalytic process (PECP). This study provides an basis for the development of a rotating PECP to water treatment.