Chemical and electrochemical surface processes attract a growing attention due to their possible practical applications. In particular, semiconducting materials and their modifications are used as catalysts and photocatalysts, electrodes, (bio)sensors etc. One of the crucial feature of an appropriate semiconductor suitable for a given purpose is the position of valence and conduction band edges at the energy (or potential) scale. For instance, the redox properties of photogenerated holes and electrons determine the activity of a photocatalyst. Therefore determination of redox potentials of semiconducting materials is very important. This knowledge helps to select the proper material and to elucidate mechanisms of processes taking place at the surface.

Although the energy bandgap can be relatively easily estimated from reflectance spectra of semiconductors, the measurement of band edge potentials is more difficult. One of the methods is based on capacity measurements. From the Mott-Schottky plot (the space charge capacity vs. electrode potential) it is possible to determine the so called flatband potential. The capacitance method is useful for semiconductor electrodes but not for suspensions. A number of other methods based on spectroscopic determinations, modulation spectroscopy, photocurrent, and photovoltage measurements have also been developed. In this presentation selected methods will be presented. Simple photoelectrochemical and spectroelectrochemical methods suitable for flatband potential measurements for semiconducting powders and transparent films will be discussed in detail.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/4832 must be provided.

1. Materiały na bazie nanokrystalicznego dwutlenku tytanu fotoaktywowane światłem widzialnym 
2. Unusual photoelectrochemical behaviour of surface-modified nanocrystalline semiconductors
3. Photocatalytic and Photoelectrochemical Properties of the Pt(IV)-Chloride Surface Modified TiO₂