Photocatalytic film of iron oxide, electrode with such a photocatalytic film, method of producing such films, photoelectrochemical cell with the electrode and photoelectrochemical system with the cell, for the cleavage of water into hydrogen and oxygen

The Photocatalytic film of semiconducting iron oxide (Fe2O3), contains an n-dopant, or a mixture of n-dopants, or a p-dopant or a mixture of p-dopants. Electrode consists of a substrate, with one ore more films or photocatalytic arrangements of film of semiconducting n-doped or p-doped iron oxide (Fe2O3) e.g. on the surface of one side of the substrate or on the surface of different sides. The photoelectrochemical cell comprises electrodes with a film or with films of the n-doped or p-doped semiconducting iron oxide (Fe2O3). The semiconducting iron oxide (Fe2O3) film can be manufactured with a spray pyrolysis process or a sol gel process. The system for the direct cleavage of water with visible light, into hydrogen and oxygen the system comprises one or more of the photoelectrochemical cells with photocatalytic films. The system can be a tandem cell system, comprising the photoelectrochemical cell with the doped iron oxide (Fe2O3) film.