Solar-driven, semi-conductor electrochemical electrolysis system for water treatment and hydrogen production

The quest for environmentally-friendly alternative energy sources with low carbon footprints is growing. Photovoltaic/electrolysis for hydrogen prodn. via water splitting using org. contaminants as sacrificial electron donors can be potential soln. In this presentation, we demonstrate the feasibility of a sub-pilot scaled rooftop hybrid photovoltaicelectrolysis system for wastewater treatment coupled with the simultaneous prodn. of hydrogen. Application of an anodic bias of > 2.0 V to bismuth-doped titanium dioxide(BiOx-TiO2)/Ti metal electrode result in the electrochem. degrdn. of a variety of org. contaminants (i.e., rhodamine B (Rh-B), methylene blue (MB), salicylic acid, triclosan, and phenol) and real wastewater from chem. industry, while mol. hydrogen is released at the counter stainless steel (SS) electrode. The kinetics of anodic substrates oxidn. is investigated as a function of the cell current, substrate concn., and background electrolyte such as NaCl and sodium sulfate, and av. current efficiencies are shown in the range of 4-22%. Cathodic current efficiency and energy efficiency for hydrogen prodn. was achieved 50-70 and 20-40 %, resp. Reactions mechanisms will be presented