Two-Dimensional Metal–Organic Framework Nanosheets Grown on Carbon Fiber Paper Interwoven with Polyaniline as an Electrode for Supercapacitors

Abstract

Metal–organic frameworks (MOFs) have been identified as potential supercapacitor electrode materials for high porosity and tunable structure. Among them, 2D MOFs combine the advantages of MOFs and 2D morphology. In this study, leaflike zeolitic imidazolate framework nanosheets (named ZIF-L) were grown onto carbon fiber paper (CFP) by a facile one-step soaking method without conductive additives or binders. As a contrast, 3D ZIF-67 nanoparticles were also used as electrode materials. The poor intrinsic conductivity and low capacity of ZIFs were improved by interweaving with polyaniline (PANI). The composite electrode (noted as CFP/ZIF-L/PANI) shows an area capacitance of 730 mF/cm2 at 10 mV/s, higher than that of CFP/ZIF-67/PANI (608 mF/cm2). The CFP/ZIF-L/PANI electrode retained approximately 82.6% of its stabilizing capacitance after 3000 cycles. In a word, this feasible method provides a direct application of pristine MOFs in the preparation of high-performance supercapacitor electrodes.

Shaping of Metal–Organic Frameworks: A Review

“…Metal–organic frameworks (MOFs) are attractive materials with abundant pore size distribution and self-assembly formed by metal ions/clusters and organic ligands through coordination bonds. − The chemical diversity allows MOFs to act as both active species as well as passive sorbents to a greater degree than zeolites or activated carbon materials. − The strong interest in MOFs has inspired the development of various synthetic approaches, including hydrothermal, , sol–gel syntheses, , electrochemical, − mechanochemical, − microwave, and ultrasound − methods. Therefore, apart from carbon capture, utilization, and storage (CCUS), − MOFs and their newly based-composites − have found broad applications in numerous fields, including catalysis, − biomedicine, , molecular adsorption/separation, − as well as electrical conduction. − There is an urgent need to combine the diversity of the structure and performance of MOFs with industrial practice. Since almost every practical application requires specific devices, it is necessary to formulate them in the right shapes for practical contactors .…”

Review on Microfluidic Construction of Advanced Nanomaterials for High-Performance Energy Storage Applications

“…As the assembly building blocks of the electrode, nanomaterials have gained great attention in energy storage applications because of their unique nano/microscale effect and enlarged physical chemistry nature. − From the perspective of dimensionality and shape, the nanomaterials contain nano/micro building blocks (nanoparticles, nanosheets, and microspheres), one-dimensional (1D) microfibers, and two-dimensional (2D) macrofabrics. − In this regard, the nano/micro building blocks are divided into nanoparticles [such as metal–organic frameworks (MOFs), conducting polymer, and metallic oxide], − nanosheets [such as graphene, MXene, black phosphorus (BP), and molybdenum disulfide (MoS 2 )], − and microspheres [such as graphene microspheres, carbon nanotube (CNT) microspheres, and hierarchical carbon microspheres]. − The 1D microfibers are constructed by nano/micro building blocks via a spinning strategy, such as a wet-spinning graphene and MXene fiber, dry-spinning CNT fiber, and electrospinning carbon fiber. − On the basis of the as-prepared 1D microfibers, the 2D macrofabrics can be further achieved by chemical cross-linking and residual-solvent-caused heat-welding between adjacent fibers, which have become important parts in energy storage applications. , For fiber preparation methods, the freedom in spinning solution guarantees that the wet spinning can be broadly used to prepare various microfiber/macrofabrics by the coagulation bath reaction. However, the non-volatile residual solvent, redundant polymer scaffold, uncontrollable fluidic force field (fluidic interfacial tension and kinetic diffusion), and many local turbulences will result in a disordered microstructure and inhomogeneous morphology.…”

Selectively Confined Poly(3,4-Ethylenedioxythiophene) in the Nanopores of a Metal–Organic Framework for Electrochemical Nitrite Detection with Reduced Limit of Detection

“…, carbon or conducting polymer. − The MOF-conducting polymer composites thus become appealing options for electrochemical applications. Several published studies have reported the design and synthesis of such MOF-based composites for electrochemical purposes, and a range of conducting polymers including polyaniline (PANI), − poly­(3,4-ethylenedioxythiophene) (PEDOT), − polypyrrole, − and polythiophene have been utilized as the conductive materials. Among these conducting polymers, PEDOT has been reported as the active material for electrochemical nitrite sensors. − We thus reasoned that the nanocomposite consisting of a highly porous and electrocatalytic porphyrinic Zr-MOF and the conductive PEDOT should further enhance the sensing performances of both pristine materials toward nitrite.…”