Excess electrons stabilized on ionic oxide surfaces.
Surface excess electrons are remarkable chemical entities that provide great opportunities for the design of new materials with precisely tuned electronic and magnetic properties. In this Account, we describe the structure and electronic properties of excess electron centers generated at the surface of insulating oxides. We also outline the elementary mechanisms that are at the basis of the generation of excess electrons at solid surfaces, setting a comparison to the general problem of excess electron localization in condensed media. Emphasis is given to morphological aspects relative to the surface-trapping sites as deduced from combined electron paramagnetic resonance and accurate quantum chemical calculations. The remarkable reactivity featured by the so formed "electron-rich" surfaces is illustrated, describing the reduction of simple diatomic molecules that form adsorbed radical anions via direct surface to adsorbate electron transfer.
Chiesa
Mario
M
Dipartimento di Chimica IFM, Università di Torino and NIS, Nanostructured Interfaces and Surfaces Center of Excellence, Via P. Giuria 7, I-10125 Torino, Italy.
Paganini
Maria Cristina
MC
Giamello
Elio
E
Murphy
Damien M
DM
Di Valentin
Cristiana
C
Pacchioni
Gianfranco
G