Solar power assisted biohydrogen evolution in microbial electrolysis cells

Photo-induced biohydrogen (PIB) production is one of the most promising biotechnology for green house gas-free and most potential energy. In this study, a two-chambered microbial electrolysis cell (MEC) was evaluated, which consists of a phototrophic anode and a platinum coated cathode. The phototrophic anode inoculated with Rhodobacter sphaeroides and heterotrophs. Photosynthetic microorganism, R. sphaeroides, converts solar energy from carbon dioxide and water into chemical energy, which is then converted into electric energy by heterotrophic bacteria such as electricigens. Then, H⁺ and e^- were transferred to the cathode and produced hydrogen. Thermodynamic barrier between the anode and the cathode in MEC generally was controlled with an external power source dependant on fossil fuel, however, it was overcome with a dye sensitized solar cell. Therefore, PIB system can produce environmental friendly hydrogen without any substrate injection and external power source.