The layered perovskite type oxides, K2La2Ti3O10 and K2La2Ti3O10 doped with B, were prepared by the sol-gel method and characterized by power X-ray diffraction and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of K2La2Ti3O10 and K2La2Ti3O10 doped with B for water splitting was investigated with I- as the electron donor under ultraviolet and visible light irradiation. The electronic structure of K2La2Ti3O10 doped with B was analyzed by the first principle calculations, which reveals the...