A visible-light responsive micro photocatalytic fuel cell with laterally arranged electrodes

Abstract

A micro photocatalytic fuel cell with a visible-light responsive photoanode and the lateral arrangement of the electrodes at the same plane was developed to enable simultaneous organics degradation and electricity generation. The developed micro photocatalytic fuel cell was assessed by using methanol as a representative organic compound in the alkaline environment. It is shown that good visible-light response was achieved. The effects of the light intensity, methanol concentration, KOH concentration and liquid flow rate were also explored. Experimental results showed that when the light intensity was increased, the cell performance was improved due to more photo-excited electron-hole pairs. Upgrading the KOH concentration led to the increased performance due to more efficient capture of the holes and enhanced cathodic reaction and ion transport. The increase of the methanol concentration in the testing range led to the improved performance as a result of the enhanced mass transport. The discharging performance was firstly increased and then decreased with increasing the liquid flow rate due to the competition of enhanced mass transfer and decreased residence time and increased methanol crossover.