Redox characterization of semiconductors based on electrochemical measurements combined with UV-Vis diffuse reflectance spectroscopy

Abstract

Several techniques can be applied to characterize redox properties of wide bandgap semiconductors, however some of them are of limited use. In this paper we propose a new modification of the old spectroelectrochemical method developed two decades ago. A procedure based on measurements of the reflectance changes as a function of potential applied to the electrode coated with the studied material appears to be a very convenient tool for characterizing redox properties of semiconductors, forming either transparent or opaque films at a platinum electrode. A discussion on the measured redox parameters of semiconductor films concludes with a definition of a new term, the absorption onset potential of the material.

Photocatalytic hydrogen evolution by co-catalyst-free TiO2/C bulk heterostructures synthesized under mild conditions

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TiO2 Processed by pressurized hot solvents as a novel photocatalyst for photocatalytic reduction of carbon dioxide

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Rhodium-doped titania photocatalysts with two-step bandgap excitation by visible light—influence of the dopant concentration on photosensitization efficiency

“…Spectroelectrochemical measurements were performed using UV-vis diffuse reectance spectroscopy combined with setup for electrochemical measurements. 31 The electrochemical setup consisted of three-electrode cell, with platinum wire and Ag/AgNO 3 as a counter and reference electrodes, respectively. Potential of the silver electrode vs. SHE estimated on the basis of the measurements of ferrocene redox potential in 0.1 M LiClO 4 solution in acetonitrile amounted to 0.56 V. Working electrode consisted of platinum foil covered with studied materials (covered area: 1 cm  1 cm).…”