New layered transition metal substituted perovskite-type oxides K(2)La(2)Ti(3-x)M(x)O(10+delta) (M = Fe, Ni, W; delta varies with different M) were synthesized with high-temperature solid state reaction, and characterized with X-ray diffraction (XRD) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activity of these catalysts was studied under ultraviolet and visible light irradiation. The results indicated that substitution of a part of Ti(4+) with Fe(3+) and W(6+) resulted in a marked increase in water splitting activity. The activity of these catalysts for water splitting decreased in the order: Fe(3+) > W(6+) > Ni(2+) >= no substitution. The effect of different amounts of Ti(4+) with Fe(3+) substitution on water splitting was also evaluated. The highest hydrogen evolution was observed for perovskite composition having a Fe:Ti molar ratio of 1:14 (1:12 weight ratio) and this hydrogen evolution was over 4 times higher than the Fe-free K(2)La(2)Ti(3)O(10) composition. Fe was also found to be a promising component for photo activity under visible light irradiation. Finally, the effect of Na(2)S/Na(2)SO(3) system as the sacrificial agent on the photocatalytic activity was also studied. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.