A Novel Amperometric Transducer Electrode with Iridium-Niobium Binary Alloys

We have discovered that an Ir-23Nb binary alloy more effectively oxidizes hydrogen peroxide than Ir, Ir-13Nb, Ir-17Nb, Ir-30Nb, Ir-43Nb, Ir-62Nb, or Nb. The oxidation capability was determined via cyclic voltammogram measurements of pH-buffer and hydrogen peroxide. We ascertained that applying a 0.7 V potential produces hydrogen peroxide currents of 9.2 mu A/mm(2) Ir-23Nb, 5.3 mu A/mm(2) Ir, 5.1 mu A/mm(2) Ir-17Nb, 3.7 mu A/mm(2) Ir-13Nb, 2.0 mu A/mm(2) Ir-30Nb, 1.5 mu A/mm(2) Ir-43Nb, 0.6 mu A/mm(2) Ir-62Nb, and 0.13 mu A/mm(2) Nb. These results indicate that the effective oxidation of Ir-23Nb for hydrogen peroxide might be due to its fcc + L1(2) two-phase structure and that Ir-23Nb can be used as an amperometric transducer material.