Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur GraphSearch.
Semiconductor photocorrosion is a major challenge for the stability of photoelectrochemical water-splitting devices. Usually, photocorrosion is studied on the basis of thermodynamic aspects, by comparing the redox potentials of water to the self-decomposition potentials of the semiconductor or analyzing the equilibrium phases at given electrolyte conditions. However, that approach does not allow for a prediction of the decomposition rate of the semiconductor or the branching ratio with the redox reaction. A kinetic model has been developed to describe detailed reaction mechanisms and investigate competition between water-splitting and photocorrosion reactions. It is observed that some thermodynamically unstable semiconductors should photocorrode in a few minutes, whereas others are expected to operate over a period of years as a result of their extremely low photocorrosion current. The photostability of the semiconductor is mainly found to depend on surface chemical properties, catalyst activity, charge carrier density, and electrolyte acidity.
,
,
Alfredo Pasquarello, Stefano Falletta, Kyriakos Stylianou, Stavroula Kampouri, Patrick Gono, Zhendong Guo