PHOTOELECTROCATALYSIS ON SEMICONDUCTORS: FROM THE FUNDAMENTALS TO ITS CONFORMATION AT THE NANOSCALE LEVEL

Abstract

The science of semiconductors, essential in electronics, is pivotal also for the most active research fields of environmental science and engineering today - the development of solar energy conversions and advanced oxidation processes, exemplified by the harvesting of sun daylight to produce electric energy, environmentally friendly fuels and to clean up water from harmful pollutants. The advancement of such fields relies on the fundamentals of the photocatalysis at semiconductors, summarized in this review in language familiar to chemists. The theory and experimental onrush emerged mainly during the first half of the 20^th century but the rising interest in the science of nanostructured materials in recent decades, besides many insights about the potential of this scale-down of sizes, also forced a revision of the theoretical models. Essentially, the interfacial model of the space-charge layer cannot explain the behavior of nanoparticulate films, even at doped conditions comparable to monocrystalline materials. The present work encompasses the conformation of classical photocatalytic models to the nanoscale size, critically reviewing their features and role for modern electrochemical applications.

Keywords:
photoelectrocatalysis; monocrystalline semiconductors; nanoparticulate semiconductors; space-charge layer; band bending