Water splitting to produce H-2 is an important procedure for the conversion of intermittent energies. However, the reaction is energetically limited by the water-oxidation process. Herein, we report the synthesis of Mn oxide on nanoparticles of KAl3(SO4)(2)(OH)(6), CO3O4, CuO, Fe3O4, MgO, NiO, SiO2, SnO2, TiO2, WO3, zeolite, ZnO and ZrO2 by a simple, low-cost and green procedure aiming at obtaining a good water-oxidizing catalyst. The obtained materials are characterized by high-resolution transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction studies. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.