Direct electrical power generation from urine, wastes and biomass with simultaneous photodecomposition and cleaning

Electric power was for the first time generated directly from urine, wastes, and biomass with simultaneous photodecomposition and cleaning by using a biophotofuel cell (BPFC) composed of a nanoporous TiO2 film semiconductor photoanode and an O2-reducing cathode. Human urine exhibited a PFC characteristics with Jsc 0.086 mA cm−2, Voc 0.56 V, and fill factor (FF) 0.50 under irradiation by a solar simulator with AM 1.5 G and 100 mW cm−2 incident light intensity. Both the soluble and residual parts of waste paper partially solubilized by a H3PO4 aqueous solution were also photodecomposed with simultaneous electrical power generation. As trials of various biomass materials, Coca-Cola (to test colored sample), Japanese rice wine (to test alcohol aqueous solution), and grated radish (to test slurry state sample) also generated effectively electrical power during photodecomposition by a solar simulator.