Patent ID: 8574421

Claim:
A water-splitting apparatus comprising: a photolysis element having an N-type water-splitting electrode surface and a P-type water-splitting electrode surface at an opposite side surface to the N-type water-splitting electrode surface, and using light irradiated on at least one of the N-type and P-type water-splitting electrode surfaces to split the water and thereby generate hydrogen at the N-type water-splitting electrode surface and generate oxygen at the P-type water-splitting electrode surface, a hydrogen generating cell holding the N-type water-splitting electrode surface and collecting the hydrogen generated at the N-type water-splitting electrode surface, and an oxygen generating cell holding the P-type water-splitting electrode surface, collecting the oxygen generated at the P-type water-splitting electrode surface, and adjoining the hydrogen generating cell across the photolysis element, wherein the N-type water-splitting electrode surface and the P-type water-splitting electrode surface of the photolysis element include through holes enabling circulation of water between the hydrogen generating cell and the oxygen generating cell, and the through holes are arranged so as not to allow light irradiated on one of the N-type and P-type water-splitting electrode surfaces for the splitting of water to pass through to the opposite side water-splitting electrode surface.