Premium
Hematite Photoanodes for Water Oxidation: Electronic Transitions, Carrier Dynamics, and Surface Energetics
Author(s) -
Li Jingguo,
Chen Hang,
Triana Carlos A.,
Patzke Greta R.
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202101783
Subject(s) - charge carrier , chemical physics , hematite , absorption (acoustics) , charge (physics) , electron , chemistry , surface charge , nanotechnology , absorption edge , materials science , band gap , optoelectronics , physics , mineralogy , quantum mechanics , composite material
We review the current understanding of charge carriers in model hematite photoanodes at different stages. The origin of charge carriers is discussed based on the electronic structure and absorption features, highlighting the controversial assignment of the electronic transitions near the absorption edge. Next, the dynamic evolution of charge carriers is analyzed both on the ultrafast and on the surface reaction timescales, with special emphasis on the arguable spectroscopic assignment of electrons/holes and their kinetics. Further, the competitive charge transfer centers at the solid–liquid interface are reviewed, and the chemical nature of relevant surface states is updated. Finally, an overview on the function of widely employed surface cocatalysts is given to illustrate the complex influence of physiochemical modifications on the charge carrier dynamics. The understanding of charge carriers from their origin all the way to their interfacial transfer is vital for the future of photoanode design.