Hybrid system for water treatment, desalination, and chemical production

A hybrid system for water treatment, desalination, and reduction of at least one chemical species, comprising a photoanode, an anode chamber comprising urea, an anion exchange membrane, a middle chamber, a cation exchange membrane, a cathode chamber comprising K2SO4 or KHCO3, and a cathode,

• wherein saltwater or seawater is desalinated by photoelectrochemical electrodialysis in the middle chamber, wastewater is treated by chlorine species generated at the photoanode from chloride ions transferred to the anode chamber during the desalination, and activated by the photoanode, and the at least one chemical species is selected from the group consisting of water, oxygen, and carbon dioxide and reduced by electrons supplied from the photoanode to the cathode in the cathode chamber,
• wherein the anode chamber and the middle chamber are separated by the anion exchange membrane, and the middle chamber and the cathode chamber are separated by the cation exchange membrane, and
• wherein the photoanode consists of TiO2, WO3, ZnO, Nb2O5, SnO2, ZrO2, SrTiO3, KTaO3, Ni—K4Nb6O17, CdS, ZnS, CdSe, GaP, CdTe, MoSe2, WSe2, BiVO4 or Fe2O3.