Abstract: Since it was found that TiO2 photoelectrodes can split water into H2 and O2 directly under UV irradiation, much research has focused on semiconductor electrodes, including doped TiO2, new materials, and heterojunctions, in efforts to improve the conversion efficiency of solar energy. Subsequently, the appearance of dye-sensitized solar cells made semiconductor electrodes practically feasible. The historical development of semiconductor photoelectrodes is briefly introduced, and their future prospects discussed.