Potassium Storage Performance of UiO-66 Derivatives from First Principles Calculations

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.

Characterizing Grain Boundary Effects on Mg2+ Conduction in Metal–Organic Frameworks

“…These ion-conductive properties of MOF have been exploited in the development of battery systems. , MOF can be utilized as an anodic anion trap to enhance Li + transference number in Li-based batteries, improving cycling stability and energy efficiency . UiO-66 and its functionalized derivatives have been explored as potential anode materials for potassium-ion batteries. , MOF as a selective separator for the suppression of unwanted species in binary-electrolyte batteries has also been demonstrated. , These studies show the viability of ion-conducting MOF and its application to battery technology. Given the diversity of MOF structures and their large potential for functionalization, a systematic approach to understanding and predicting ion transport properties can accelerate the further development of MOF-based ion conductors.…”

“…13 UiO-66 and its functionalized derivatives have been explored as potential anode materials for potassium-ion batteries. 14,15 MOF as a selective separator for the suppression of unwanted species in binary-electrolyte batteries has also been demonstrated. 16,17 These studies show the viability of ionconducting MOF and its application to battery technology.…”

Theoretical and Experimental Study for Cross-Coupling Aldol Condensation over Mono- and Bimetallic UiO-66 Nanocatalysts

“…These results also agree with the data obtained from our previous work 59 and other published work. 60,61 The interacting systems mono-and bimetallic UiO-66/acetone and UiO-66/ benzaldehyde were simulated by means of DFT methods. The optimized structures of the ground electronic states of monoand bimetallic UiO-66 with acetone or benzaldehyde are displayed in Table S8.…”

Review on 3D Printing of Bioinspired Structures for Surface/Interface Applications

“…The second method is to directly construct the microstructure on the surface of the substrate by etching printing and filling it with lubricant to form the super‐slippery surface. [ 135–137 ] Most of the super‐slippery surface obtained by this method has high structural stability and strong durability.…”