Transparent regenerative photoelectrochemical cell

A regenerative photoelectrochemical cell (1) including a first transparent substrate (2) comprising a first transparent electrode (6), and a second transparent substrate (4) comprising a second transparent electrode (8) on which a first photoelectrochemically active semiconductor oxide layer (10) is deposited as a porous nanostructure of sintered colloidal particles (12). Said substrates (2, 4) are arranged so as to define a space filled with an electrolyte (16) impregnating said porous structure in such a way that it contacts both the electrode (6) on the first substrate (2) and the electrode (8) on the second substrate (4). The second substrate further comprises a second, continuous and dense semiconductor oxide layer (20) extending between the second electrode (8) and the first semiconductor oxide layer (10).