Sub-pilot-scale hybrid electrochemical system for hydrogen production and wastewater treatment using solar panel

There is a need for both environmentally-friendly alternative energy resources and advanced wastewater treatment technologies. We demonstrates sub-pilot scaled hybrid photovoltaic (PV)-electrolysis system for hydrogen production via water electrolysis with simultaneous wastewater treatment. Application of > 2.0 V to bismuth-doped TiO₂ (BiO_x-TiO₂)/Ti metal electrode results in the electrochemical oxidation of various organic contaminants (e.g., methylene blue and phenol) and real wastewater, while molecular hydrogen is produced at the counter stainless steel (SS) electrode. The kinetics of anodic substrates oxidation is investigated as a function of the cell current (Icell), substrate concentration, and background electrolytes and average current efficiencies are shown in the range of 4-22 %. Cathodic current efficiency and energy efficiency for hydrogen production was achieved at 50-70% and 20-40%, respectively. For practical application, a solar-powered hybrid electrochemical system is also investigated using a commercial photovoltaic (PV) array.