A facile and low-cost method is developed to ion implant platinum nanoparticles (PtNPs) onto indium tin oxide (ITO) electrode. This modified electrode is eco-friendly without the use of any linking chemicals. The PtNPs formed on the electrode are in the zero-valent metallic state with a size distribution in the range of 5-12 nm. The modified electrode surface becomes smoother after platinum ion implantation and the PtNPs formed on the electrode. Electrochemical performances are measured by cyclic voltammetry (CV) and chronoamperometric. The PtNPs/ITO electrode shows prominent electrocatalytic activity towards the oxidation of formaldehyde with long-term stability, which could be useful in fuel cells. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.