A WO3/Ag-B-i based oxygen-evolution catalyst, combining an Ag-B-i catalyst with WO3, has been prepared. This catalyst shows excellent catalytic activity for the splitting of water under mild conditions (near neutral, room temperature, and atmospheric pressure). The WO3/Ag-B-i catalyst shows a high oxygen-evolution rate (30.85 mu mol/h), a high Faradaic efficiency (91.30%), and a low oxygen-evolution overpotential (290 mV). Oxygen evolution and stability performance have been investigated by electrochemical measurements. The WO3/Ag-B-i catalyst has been further characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS). Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.