Indexed by:
Abstract:
The potassium storage performance of UiO-66 derivatives was investigated by density functional theory calculations. The calculation results show that the substitution of all Zr in nodes of UiO-66 by Ti reduces the band gap. During potassiation, UiO-66-Ti and UiO-66-Hf have similar charge transfer processes to UiO-66, in which the charges of Ti and Hf are almost not changed, and the charge transfers from K to C or O near it. Compared with UiO-66, UiO-66-Hf has a lower theoretical capacity (490 mAh/g) with a smaller volume expansion and a slightly higher energy barrier for K-ion diffusion. UiO-66-Ti has a lower diffusion barrier for K ion although it has a larger volume expansion with all sites occupied by K. For the -NH2, -NO2, -Br, -Cl, -OH, -SH, and -CH3 functionalized UiO-66, the substitutions of H in ligands reduce the band gap of UiO-66, with the largest reduction in UiO-66-NH2. The p orbitals of N in the NH2 contribute greatly to the reduction of the band gap. The K intercalated at the K2(L) and K3 sites during the charging process will transfer part of the electrons to the substituents. Between the Zr6O4(OH)(4) nodes, there will be a migration path that crosses the substituent, and the diffusion energy barrier on this path is smaller than that of the original path of UiO-66. The results suggest that proper modification of UiO-66 can improve its electronic conductivity and ionic conductivity as the anode of potassium ion battery.
Keyword:
Reprint 's Address:
Email:
Version:
Source :
JOURNAL OF PHYSICAL CHEMISTRY C
ISSN: 1932-7447
Year: 2022
Issue: 9
Volume: 126
Page: 4286-4295
3 . 7
JCR@2022
3 . 3 0 0
JCR@2023
ESI Discipline: CHEMISTRY;
ESI HC Threshold:74
JCR Journal Grade:2
CAS Journal Grade:3
Cited Count:
WoS CC Cited Count: 9
SCOPUS Cited Count: 5
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 1
Affiliated Colleges: