A novel tandem photoelectrochemical cell utilizing low-cost and non-critical raw materials was developed to produce green hydrogen via water splitting. The photoanode is composed of a hematite-based material layered on a fluorine-doped tin oxide glass for the oxygen evolution reaction, while the photocathode is made of CuO deposited on a hydrophobic gas diffusion layer for the hydrogen evolution reaction. An anionic polymeric membrane is placed between the photo-electrodes and used as the electrolyte and gas separator, with a low crossover of hydrogen and oxygen that guarantees the operational stability of the cell and efficient separation of water-splitting products.