Novel photocatalysts, protonated layered perovskite oxides H-ABi(2)Ta(2)O(9) (A = Ca, Sr, Ba, K0.5La0.5) for overall water splitting were synthesized by ion exchange with acid treating. The characterization by XRD, HRTEM indicated that all of H-ABi(2)Ta(2)O(9) (A = Ca, Sr, Ba, K0.5La0.5) were able to form new single-phase protonated layered oxides. The measurement of photocatalytic activity showed every protonated layered oxide could overall split water into H-2 and O-2, although the ratios of H-2 and O-2 are unstoichiometric. The sequence of photocatalytic H-2 production is HCBT(107.0 mu mol/h) < HBBT(119.5 mu mol/h) < HSBT(162.7 mu mol/h) < HKLBT(189.3 mu mol/h). The difference of ionic radius of cations in interlayer influenced the band gaps, and resulted in the distinction of photocatalytic activity. Pt loading enhanced apparently the photocatalytic activity. Among all of photocatalysts in this study, 0.1 wt%Pt/HSBT showed the highest photocatalytic activity for H-2 evolution, reaching 491 mu mol/h. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.