Herein we report a new method to synthesize highly dispersed PtO2 on layered Mn oxide. The compound was characterized by scanning electron microscopy, energy dispersive spectrometry, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and atomic absorption spectroscopy. Then, we investigated the role of PtO2 on the water-oxidizing activity of nanolayered Mn in the presence of cerium (IV) ammonium nitrate as a non-oxo transfer oxidant. The water-oxidizing activities of these composites with other previously reported Mn oxides are compared and also the important factors influencing the water-oxidizing activities of Mn oxides are discussed. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.