Electrolyte Electroreflectance Study of the Oscillatory Hydrogen Peroxide Reduction on n-GaAs

Abstract

The oscillatory reduction of hydrogen peroxide on an n-type gallium arsenide electrode was studied by means of the electrolyte electroreflectance technique. It is found that during the current oscillations both the reflectivity and electroreflectance oscillate with qualitatively different patterns. A simple model, which attributes the current oscillations to an anomalous dependence of the band bending in the semiconductor depletion layer on the potential drop across the semiconductor/electrolyte interface, is considered for comparison. It is concluded that the absolute reflectivity detects a slow variable of the system, most likely related to the chemical composition of the surface, and the electroreflectance detects a fast variable of the system, most likely related to the interfacial potential distribution.

Investigation of nanostructured TiO2 surface and interface electric fields with photoreflectance spectroscopy

“…Evidence to this effect stems from ER spectra of hydrogen peroxide terminated n‐type, single crystal GaAs(100) in solution . Koper and coworkers identified two distinct contributions to their ER spectra: one having to do with field modulation in the space charge layer and the other, a direct spectral manifestation of surface states.…”

Mechanisms of Two Electrochemical Oscillations of Different Types, Observed for H2O2 Reduction on a Pt Electrode in the Presence of a Small Amount of Halide Ions

“…Electrochemical oscillations have been reported for a variety of systems, as summarized in recent reviews, − including anodic metal dissolution, , cathodic metal deposition, oxidation of hydrogen molecules , and small organic compounds such as formic acid, , formaldehyde, , and methanol, and reduction of hydrogen peroxide, − ,, persulfate ions, etc. The electrochemical oscillations have thus far been classified by the kind of oscillating reactions or the conditions under which oscillations are observed.…”

New-Type Electrochemical Oscillation Caused by Electrode−Surface Inhomogeneity and Electrical Coupling as Well as Solution Stirring through Electrochemical Gas Evolution Reaction

“…Chemical oscillations are representative examples of nonlinear chemical phenomena. Recently, a large number of oscillatory phenomena have been reported, in particular in the field of electrochemistry, as summarized in recent reviews. − The mechanisms of electrochemical oscillations have been studied successfully − especially since the work of Koper and Sluyter. , Very recently, Strasser et al classified electrochemical oscillations on the basis of the mechanisms and proposed four categories, classes I, II, III (negative differential resistance [NDR] oscillators), and IV (hidden negative differential resistance [HNDR] oscillators). They also reported 17 that most electrochemical oscillations fell into class III and class IV categories.…”