Kinetics and Mechanism of the Hydrogen Peroxide Reduction Reaction on a Graphite Carbon Nitride Sensor

Mariana I. Rojas, Oliviero Andreussi, Cesar G. Gomez, Lucía B. Avalle

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

The kinetics and mechanism of the hydrogen peroxide reduction reaction (HPRR) on a recently proposed carbon-based electrode is studied by means of experiments and simulations. The electrode is highly oriented pyrolytic graphite (HOPG) modified by the deposition of a graphite carbon nitride (g-C3N4) film. Current transients obtained from chronoamperometry measurements allow us to propose a kinetic model for the HPRR on the surface. The model produces excellent fits of current transients, providing sensible rate constants for each electrocatalytic step. The rate constants obtained are consistent with low energy barriers for each step, suggesting outstanding electrocatalytic activity of the g-C3N4/HOPG electrode. Moreover, different trends are found for low and high analyte concentrations, evidencing a change in the reaction mechanism. To clarify the mechanisms involved in the reaction, first-principles atomistic simulations were performed. The different reaction steps were modeled at the substrate/water interface, including solvent environment through continuum embedding approaches. The simulated thermodynamics and kinetics of the different processes show that a significant role in the electrocatalytic activity of the system is associated with the geometrical rearrangements of the interface, with a critical role played by the corrugation/decorrugation processes of the outermost sheet of the electrode.

Original languageEnglish
Pages (from-to)336-346
Number of pages11
JournalJournal of Physical Chemistry C
Volume124
Issue number1
DOIs
StatePublished - 9 Jan 2020

Fingerprint

Dive into the research topics of 'Kinetics and Mechanism of the Hydrogen Peroxide Reduction Reaction on a Graphite Carbon Nitride Sensor'. Together they form a unique fingerprint.

Cite this