Self-assembly of Active IrO2 Colloid Catalyst on an ITO Electrode for Efficient Electrochemical Water Oxidation

J Phys Chem B. 2005 Nov 24;109(46):21489-91. doi: 10.1021/jp0550208.


Active catalysts for water oxidation to evolve O(2) are required for the construction of artificial photosynthetic devices that are expected to be promising energy-providing systems in the future. The citrate-stabilized IrO(2) colloid was self-assembled onto an indium tin oxide (ITO) electrode to form a monolayer of the colloidal IrO(2) particles when it was dipped in the colloid solution. The self-assembly could be achieved by a chemical interaction between carboxylate groups on the citrate stabilizer and hydroxyl groups on the ITO surface to form ester bonds. Efficient electrocatalysis for water oxidation was demonstrated using the electrode modified by the self-assembled IrO(2) colloid to yield the highest turnover frequency ((2.3-2.5) x 10(4) h(-1)) of IrO(2) in the hitherto-reported catalysts for electrochemical water oxidation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Colloids / chemistry*
  • Electrochemistry
  • Electrodes
  • Iridium / chemistry*
  • Oxidation-Reduction
  • Oxygen / chemistry*
  • Time Factors
  • Tin Compounds / chemistry*
  • Water / chemistry


  • Colloids
  • Tin Compounds
  • Water
  • iridium oxide
  • Iridium
  • indium tin oxide
  • Oxygen