TY - JOUR
T1 - Charge Transport over the Defective CeO2(111) Surface
AU - Su, Ya Qiong
AU - Filot, Ivo A.W.
AU - Liu, Jin Xun
AU - Tranca, Ionut
AU - Hensen, Emiel J.M.
PY - 2016/8/23
Y1 - 2016/8/23
N2 - First-principles calculations have been performed to explore the charge transport process over defective CeO2(111). Charge transport can proceed either by direct migration of the oxygen anion (i.e., vacancy diffusion) or by a polaron-hopping-assisted mechanism. On the basis of DFT+U calculations, we found that the latter process is significantly more favorable than the former. The overall barrier for charge transport involving polaron migration, followed by oxygen diffusion, is determined by the barrier for polaron hopping, which amounts to 0.18 eV. This computed value is in good agreement with the experimental barrier for ceria with a low defect density. We have shown by a careful analysis of the magnetization density, the density of states, and the reaction pathway trajectory that this process is phonon induced. Our results provide valuable insights into carrier drift processes over defective metal oxide surfaces.
AB - First-principles calculations have been performed to explore the charge transport process over defective CeO2(111). Charge transport can proceed either by direct migration of the oxygen anion (i.e., vacancy diffusion) or by a polaron-hopping-assisted mechanism. On the basis of DFT+U calculations, we found that the latter process is significantly more favorable than the former. The overall barrier for charge transport involving polaron migration, followed by oxygen diffusion, is determined by the barrier for polaron hopping, which amounts to 0.18 eV. This computed value is in good agreement with the experimental barrier for ceria with a low defect density. We have shown by a careful analysis of the magnetization density, the density of states, and the reaction pathway trajectory that this process is phonon induced. Our results provide valuable insights into carrier drift processes over defective metal oxide surfaces.
UR - http://www.scopus.com/inward/record.url?scp=84983684783&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.6b01548
DO - 10.1021/acs.chemmater.6b01548
M3 - Article
AN - SCOPUS:84983684783
SN - 0897-4756
VL - 28
SP - 5652
EP - 5658
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 16
ER -