Enhancement of azo dye degradation and power generation in a photoelectrocatalytic microbial fuel cell by simple cathodic reduction on titania nanotube arrays electrode

The research provides a simple method for high-performance electrode preparation for use with a microbial fuel cell and microcurrent to treat pollutants. Blue titania nanotube arrays as a new microbial fuel cell electrode is synthesized by cathodic reduction. The results show that these arrays remarkably increase the electricity generation from 3.64 +/- 0.112 mA to 6.246 +/- 0.135 mA at the bioanode. A higher carrier concentration of 4.70 x 10(24) cm(-3), an apparent electron transfer rate constants of 21.69 ms(-1) and drastic decrease in resistance to 1352 Omega provide better conditions for electroactive bacteria accumulation. The application of blue titania nanotube arrays to both the anode and cathode results in a photo-microbial fuel cell capable of efficient photoelectrocatalytic degradation of azo dye. The degradation of the azo dye and its intermediate products is attributed to electronic reduction of the dye and oxidation by free radicals.