Electrochemical oxidation of hydrogen peroxide at platinum electrodes. Part 1. An adsorption-controlled mechanism

Hydrogen Peroxide Detection at Electrochemically and Sol‐Gel Derived Ir Oxide Films

“…The apparent Michaelis-Menten constants (K m ') for the three curves in Figure 6 are ff, 14 and 16 mM, increasing with an increase in IrOx film thickness. Analogous to what was reported by Hall et al [12] for H 2 0, oxidation at Pt, this behavior may indicate the adsorption of H 2 0 2 on the IrOx surface. This is also consistent with the fact that Figure 6 shows an increase in current density with increasing film thickness (increasing number of IrOx sites).…”

“…Even lower potentials (0.35 V) can be used in chronoamperometric experiments, giving apparent Michaelis-Menten constants, K' m in the range of 11-16 mM and a maximum current of 0.5-2 mA cirr 2 . The fact that a limiting oxidation current is reached at high H 2 0 2 concentrations suggests that adsorption of H 2 0 2 on IrOx occurs, analogous to Hall's study [12] at Pt. IrOx electrodes also offer a higher linear detection range for H 2 0 2 oxidation (up to at least 12 mM in CV experiments) than at other metallic electrodes.…”

“…1 and 2, is no longer seen, and the mode of detection of H : 0 : prevailing now is via its reduction and oxidation, as has also been reported for Pt [5][6][7][8][9][10][11] and other metallic [12][13][14][15][16][17] or metallized [20] electrodes. Figure 3 demonstrates the reduction and oxidation of 2 and 4 mM H 2 0 2 on metallic Ir in a pH 7 phosphate buffer solution.…”

“…The glucose detection in this biosensor was realized via the oxidative detection of H 2 0 2 , but the role of IrOx in H 2 0 2 oxidation was not examined closely. Taking into consideration that the formation of Pt and Pd oxide has been linked to the catalytic properties of metallic Pt and Pd electrodes towards H 2 0 2 oxidation [5][6][7][8]10,12,14,15], the involvement of IrOx in the H 2 0 2 redox processes seems likely. However, it has also been suggested [21 -29] that the metal plays the key role in the reductive response of a glucose biosensor consisting of Pt, Pd, Ir or Ru co-deposited with GOx.…”

Detection of Glutamate and Acetylcholine with Organic Electrochemical Transistors Based on Conducting Polymer/Platinum Nanoparticle Composites

“…Platinum is known for its catalytic activity in the oxidation of H2O2. [7] Indeed, platinum micro-electrodes have recently been used to detect both glutamate and acetylcholine in vivo. [8] This work has paved the way for efficient in-situ monitoring of neurotransmitters, in part thanks to the excellent electrocatalytic activity of Pt toward H2O2 oxidation.…”