PbO2 nanowires that were approximately 200 nm in diameter were obtained by template electrodeposition using an anodic aluminum oxide membrane. A proton exchange membrane (PEM) water electrolyzer with an anode made of this PbO2 nanowire, a cathode made of carbon supported platinum, and Nafion (R)-117 membrane operating at a current density of 1.5 A cm(-2), an ozone current efficiency of 20% was achieved, and did not attenuate significantly during a 30-day period. (C) 2016 Elsevier Ltd. All rights reserved.