Influence of operating parameters on the bio-photoelectrochemical cell for hydrogen and electricity production

Hydrogen and electricity can be produced simultaneously via a dual chamber bio-photoelectrochemical cell. This cell is designed with a proton exchange membrane to separate the bio-anode and the n-type titanium dioxide photocathode. The effects of photocathode size, catholyte pH, illumination intensity, and external resistance on electricity and hydrogen production are investigated. By increasing the photocathode size or decreasing catholyte pH, the performance for hydrogen and electricity production increases. By using photocathode size of 3 cm² at neutral pH, the highest power density of 47.4 mW m^-2 was obtained under 350 W light irradiation. Hydrogen production rate of 14.1 uL h^-1 can be achieved with external resistance of 1,000 Ω.