Hydrogen production by hybrid process combined with assistance of solar and electric energies

To increase the efficiency for hydrogen production by solar decomposition of water in the photoelectrochemical local cell, it was advantageous to decompose an acidic aqueous electrolyte containing Fe³⁺ ions. In the photo-cell having an n-type semiconductor anode illuminated with solar light, the electrolyte decomposed to oxygen and Fe²⁺ ions with a quantum efficiency of ca 38% for light below 400 nm. The electrolyte containing the Fe²⁺ ions produced was electrolysed in the cell having a packed bed carbon anode and a platinum cathode deposited on a cation exchange membrane, producing hydrogen and Fe³⁺ ions with less than 1.0 V at 50 mA cm^?2 and was then fed back to the photo-cell.