Tunable Electrochemistry of Electrosynthesized Copper Metal–Organic Frameworks

Abstract

Metal–organic frameworks (MOFs) synthesized using different organic ligands are expected to have varied morphology and properties. Herein, three copper MOFs (Cu‐MOFs) are electrosynthesized using a simple and direct reduction approach and three organic ligands: 1,3,5‐benzenetricarboxylic acid, 1,4‐benzenedicarboxylic acid, and 1,2,4,5‐benzenetetracarboxylic acid. The as‐synthesized Cu‐MOFs exhibit varied morphology. Their electrochemistry is further explored via investigating the natures of their capacitive, faradaic, and electrocatalytic behavior. The stability of these Cu‐MOFs is also checked during the course of electrochemical measurements. The secondary built units of organic ligands with copper ions are found theoretically and experimentally to determine both the morphology and active sites of Cu‐MOFs. Namely the electrochemistry of Cu‐MOFs is dependent on the used organic ligands. Cu‐MOF synthesized using 1,3,5‐benzenetricarboxylic acid owns better electrochemistry than that using 1,4‐benzenedicarboxylic acid or 1,2,4,5‐benzenetetracarboxylic acid. These MOFs keep their compositions and crystallinity unchanged in short times but loss them for long electrochemical running times. Therefore, the properties and applications of MOFs are designable and can be optimized during the course of reduction electrosynthesis processes via selecting organic ligands and metal ions.

Convergent and Divergent Paired Electrodeposition of Metal-Organic Framework Thin Films

“…On the other hand, fragility and insolubility of most bulk MOF crystals are deficiencies of these compounds for modification of surfaces 15–18 . To overcome these drawbacks, considerable scientific efforts have been devoted to stabilization of MOFs as thin films 16–22 . From a comprehensive perspective, two general categories can be mentioned; ex-situ and in-situ techniques 16–23 .…”

“…The former methods need to transfer of synthesized MOFs onto the substrate and therefore are less acceptable than the in-situ , or direct growth/deposition techniques with an intergrowth and integrated thin films. Meanwhile, electrochemistry is still a niche and unique platform to address the interfacing issue of MOFs with the underlying surface 16,22,24,25 . This positive glance comes from the mild, one-step, selective and controllable strategy that would lead to the simultaneous synthesis and deposition of large-area and uniform films 16,25 .…”

“…This positive glance comes from the mild, one-step, selective and controllable strategy that would lead to the simultaneous synthesis and deposition of large-area and uniform films 16,25 . Among the electrochemistry approaches that have been dedicated toward the in-situ /direct modification, anodic and cathodic techniques for micro- and mesoporous MOFTFs are easy on the eyes 15,16,18,22,25–31 . In the anodic method that electrode plays the role of cation source, non-blocking of pores by salt and controlling of metal oxidation state are its beneficial features 15,16,26,29 .…”

Electroforming of a metal–organic framework on porous copper hollow fibers

“…18,19 It is crucial to note the distinct difference between MOF powder synthesis and lm formation. 17,18,22,24,31,35,[61][62][63] Our results show that a decrease in the current is not detrimental but can result in the formation of more uniform lms. Cu-BTC-coated Cu HFs prepared without the supporting electrolyte are promising candidates for future applications such as gas separation or catalysis.…”

Oxygen‐Assisted Cathodic Deposition of Zeolitic Imidazolate Frameworks with Controlled Thickness

“…However, reports on the cathodic deposition of MOFs are comparably few. The challenge arises from the more negative reduction potential of nitrate ions relative to those of some important metal ions, for example, Zn II , Co II , and Cu II , which constitute the most extensively studied MOFs ,. As a result, cathodic deposition of these MOF materials is commonly accompanied with plating of the corresponding metals,, which is in most cases undesirable.…”