scholarly journals Insights in the Ionic Conduction inside Nanoporous Metal-Organic Frameworks by Using an Appropriate Equivalent Circuit

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4352
Author(s):  
Abhinav Chandresh ◽  
Zejun Zhang ◽  
Lars Heinke
Keyword(s):  
Equivalent Circuit ◽  
Physical Meaning ◽  
Ionic Conduction ◽  
Electrochemical Impedance ◽  
Metal Organic Frameworks ◽  
Nanoporous Metal ◽  
Reference Circuit ◽  
Metal Organic ◽  
Electrode Interface

The conduction of protons and other ions in nanoporous materials, such as metal-organic frameworks (MOFs), is intensively explored with the aim of enhancing the performance of energy-related electrochemical systems. The ionic conductivity, as a key property of the material, is typically determined by using electrochemical impedance spectroscopy (EIS) in connection with a suitable equivalent circuit. Often, equivalent circuits are used where the physical meaning of each component is debatable. Here, we present an equivalent circuit for the ionic conduction of electrolytes in nanoporous, nonconducting materials between inert and impermeable electrodes without faradaic electrode reactions. We show the equivalent circuit perfectly describes the impedance spectra measured for the ion conduction in MOFs in the form of powders pressed into pellets as well as for MOF thin films. This is demonstrated for the ionic conduction of an aprotic ionic liquid, and of various protic solvents in different MOF structures. Due to the clear physical meaning of each element of the equivalent circuit, further insights into the electrical double layer forming at the MOF-electrode interface can be obtained. As a result, EIS combined with the appropriate reference circuit allows us to make statements of the quality of the MOF-substrate interface of different MOF-film samples.

scholarly journals Conductivity measurement of ionic liquids confined in the nanopores of metal–organic frameworks: a case study for [BMIM][TFSI] in HKUST-1

Ionics ◽  
2021 ◽  
Author(s):  
Zejun Zhang ◽  
Chun Li ◽  
Abhinav Chandresh ◽  
Lars Heinke
Keyword(s):  
Ionic Liquids ◽  
Impedance Spectroscopy ◽  
Ionic Conduction ◽  
Electrochemical Impedance ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Conductivity Measurement ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Metal Organic

AbstractNanoporous materials like metal–organic frameworks (MOFs) attract considerable attention as porous host for electrolytes like ionic liquids (ILs). The conductivity and mobility of the ions in the pores are among the key properties and their experimental quantification is of paramount importance. Here, three different approaches for the quantification of the ion conductivity of IL@MOF via electrochemical impedance spectroscopy (EIS) are compared: the material in the form of IL-impregnated MOF powders pressed into pellets between two planar electrodes, MOF films grown on substrates with deposited electrodes loaded with IL by impregnation, and the IL-loaded MOF films where excess IL is removed. Contact-angle measurements and EIS data show that the excess IL on the outer MOF surface of the film or pellet results in apparent conductivities, larger than the intrinsic conductivity of the IL@MOF. Removing the excess IL enables the experimental quantification of the intrinsic IL@MOF conductivity. Graphical abstract The ionic conduction of ionic liquid (IL) confined in nanoporous metal–organic framework (MOF) is explored via impedance spectroscopy, where the material is either in the form of pellets pressed from powder or in the form of thin films grown on suitable substrates. The different methods show substantially different results, attributed to excess IL on the external surface, and a method for recording the intrinsic IL@MOF conductivity is presented.

Negative linear compressibility in nanoporous metal-organic frameworks rationalized by the empty channel structural mechanism

2021 ◽  
Author(s):  
Francisco Colmenero
Keyword(s):  
Crystal Structures ◽  
Metal Organic Frameworks ◽  
Structural Mechanism ◽  
Nanoporous Metal ◽  
Metal Organic ◽  
Linear Compressibility

Cobalt squarate hydroxide (Co3(C4O4)2(OH)2), zinc squarate tetrahydrate (ZnC4O4·4 H2O) and titanium oxalate trioxide dihydrate (Ti2(C2O4)O3·2 H2O) are nanoporous metal-organic frameworks possessing empty channels in their crystal structures. The crystal structures...

MOF-based electronic and opto-electronic devices

2014 ◽  
Vol 43 (16) ◽  
pp. 5994-6010 ◽  
Author(s):  
V. Stavila ◽  
A. A. Talin ◽  
M. D. Allendorf
Keyword(s):  
Electronic Devices ◽  
Metal Organic Frameworks ◽  
Emergent Properties ◽  
Ordered Structure ◽  
Nanoporous Metal ◽  
Metal Organic

Emergent properties resulting from the ordered structure and synthetic versatility of nanoporous metal–organic frameworks offer exciting possibilities for electronic devices.

ChemInform Abstract: Crystal Growth of Nanoporous Metal Organic Frameworks

ChemInform ◽  
2012 ◽  
Vol 43 (23) ◽  
pp. no-no
Author(s):  
Martin P. Attfield ◽  
Pablo Cubillas
Keyword(s):  
Crystal Growth ◽  
Metal Organic Frameworks ◽  
Nanoporous Metal ◽  
Metal Organic

Encapsulation of hemin in Fe-based metal-organic frameworks and its application for the direct determination of aflatoxin M1

2021 ◽  
pp. 1-10
Author(s):  
F. Jahangiri-Dehaghani ◽  
H.R. Zare ◽  
Z. Shekari
Keyword(s):  
Electrochemical Impedance ◽  
Metal Organic Frameworks ◽  
Direct Determination ◽  
Differential Pulse ◽  
Aflatoxin M1 ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
Selective Determination ◽  
Metal Organic

A label-free electrochemical aptasensor was constructed for the sensitive and selective determination of AFM1. For preparation of the aptasensor, the AFM1 aptamer was immobilised on the surface of a glassy carbon electrode modified with hemin encapsulated in Fe-based metal-organic frameworks (hemin@Fe-MIL-101). The morphology and the structure of Fe-MIL-101 and hemin@Fe-MIL-101 were evaluated by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction and Brunauer-Emmett-Teller-N2 sorption methods. Electrochemical impedance spectroscopy and cyclic voltammetry were performed to monitor the fabrication process of the electrochemical aptasensor. The electrochemical reduction current of hemin encapsulated in Fe-MIL-101 serves as a signal for the quantitative determination of AFM1. Differential pulse voltammetry was done to determine the AFM1 concentration in the linear range of 1.0×10-1-100.0 ng/ml. The detection limit of AFM1 was estimated to be 4.6×10-2 ng/ml. Finally, the fabricated aptasensor was applied to determine AFM1 in raw and boiled milk samples.

Synthesis and Electrochemical Properties of Ternary Co-, Cu- and Ni- Based Metal-Organic Frameworks Electrode for Battery Supercapacitor Hybrid Application

2020 ◽  
Vol 981 ◽  
pp. 17-22
Author(s):  
Amir Luqman Sanusi ◽  
Nurul Khairiyyah Mohd Zain ◽  
Izan Izwan Misnon ◽  
Ahmad Salihin Samsudin ◽  
Rajan Jose
Keyword(s):  
Electrochemical Properties ◽  
Metal Ion ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Metal Organic Frameworks ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
Electrochemical Analysis ◽  
Benzenedicarboxylic Acid ◽  
Metal Organic

Metal-organic frameworks (MOFs) composed by coordination bonds between metal ion with organic linker has a uniform combination of micro and mesoporous structures has been used for several application including battery supercapacitor hybrid. (BSH). In BSH, MOF offer several advantages including high surface area, porous, and structure tunability. This paper reports the synthesis of ternary MOF of copper (Cu), nickel (Ni) and cobalt (Co) with 1,4-benzenedicarboxylic acid. The Co/Cu/Ni-MOF is synthesized using hydrothermal method at 160 °C for 12h and further develop as a BSH electrode. The physicochemical properties of MOF were characterized using FESEM, FTIR, XRD, BET and the electrochemical properties were evaluated using cyclic voltammetry (CV), charge-discharge cycling (CDC) and electrochemical impedance spectroscopy (EIS). Electrochemical analysis indicated that the MOF has high specific capacitance (CS) of 591 F g-1 at a current density of 1 A g-1 and 519 F g-1 at scan rate of 2 mV s-1, and possess low series resistance (RS) of 0.44 Ω and equivalent distributed resistance (Rd) of 1.07 Ω.

Colloidal Route for Preparing Optical Thin Films of Nanoporous Metal-Organic Frameworks

2009 ◽  
Vol 21 (19) ◽  
pp. 1931-1935 ◽  
Author(s):  
Patricia Horcajada ◽  
Christian Serre ◽  
David Grosso ◽  
Cedric Boissière ◽  
Sandrine Perruchas ◽  
...  
Keyword(s):  
Thin Films ◽  
Metal Organic Frameworks ◽  
Nanoporous Metal ◽  
Metal Organic

scholarly journals Front Cover: Multi-Component Uptake of Dye Molecules by Films of Nanoporous Metal-Organic Frameworks (ChemPhysChem 24/2017)

ChemPhysChem ◽  
2017 ◽  
Vol 18 (24) ◽  
pp. 3504-3504
Author(s):  
Mahnaz Saghanejhadtehrani ◽  
Erik K. Schneider ◽  
Lars Heinke
Keyword(s):  
Metal Organic Frameworks ◽  
Dye Molecules ◽  
Front Cover ◽  
Nanoporous Metal ◽  
Metal Organic
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