Potential-Tunable Metal–Organic Frameworks: Electrosynthesis, Properties, and Applications for Sensing of Organic Molecules

Abstract

Properties of metal–organic frameworks (MOFs) are determined by metal centers, organic ligands, and applied synthesis methods. For electrosynthesis of MOFs, the applied potential is expected to play a key role in determining the morphology, thickness, electrochemical properties, and applications of MOFs. Herein, Cu-BTC (H3BTC: 1,3,5-benzenetricarboxylic acid) films are electrosynthesized at different cathodic potentials. They feature different morphologies, thicknesses, and amounts of active copper centers, although they do show similar bonding properties, chemical compositions, phase purity, crystallinity, and surface electronic states of copper centers. Using nicotine amide adenine dinucleotide, the sensing application of these Cu-BTC films is explored, showing potential-dependent catalytic ability. Further monitoring of six other organic compounds (herein xanthine, hypoxanthine, diethylstilbestrol, estradiol, sunset yellow, and tartrazine) reveals the morphology and thickness of Cu-BTC films and the amount of copper centers inside these Cu-BTC films determines the accumulation or sensing ability of Cu-BTC films. Highly sensitive detection of these molecules individually and simultaneously is achieved with Cu-BTC electrosynthesized at −1.30 V. Electrosynthesized Cu-BTC films are thus excellent electrode materials for sensitive sensing of various analytes.

Electrodeposited Metal Organic Framework toward Excellent Hydrogen Sensing in an Ionic Liquid

“…Fabrication of such coatings can be used for catalysis 25 , microelectronics, separation 22 and sensing [26][27] . However, the synthesis parameters [28][29] play an important role in the final form of the synthesized thin films of MOFs 30 .…”

“…Such synthesis techniques require the extensive use of chemicals and specific activation techniques (e.g., solvent extraction and heating), which may take up to several days. − In recent years, MOFs have attracted attention in thin film coatings, owing to their tunable properties and ease of synthesis even at room temperature. − Various methods of thin film formation of MOFs have been reported, such as the dipping method by exposing substrates to precursor solutions, chemical vapor deposition (CVD), anodic dissolution, and cathodic electrodeposition . Fabrication of such coatings can be used for catalysis, microelectronics, separation, and sensing. , However, the synthesis parameters , play an important role in the final form of the synthesized thin films of MOFs …”

2D Graphene Oxide/Fe-MOF Nanozyme Nest with Superior Peroxidase-Like Activity and Its Application for Detection of Woodsmoke Exposure Biomarker

“…Nanozymes are considered as promising substitutes of natural enzymes for ELISA, among which MOFs have been reported as high-efficiency and economical nanozymes due to their outstanding surface area and abundant active sites. − However, a major issue is to improve their poor water solubility and inferior catalytic activity compared to HRP . As for the applications of nanozymes in biological assays, good water solubility or dispersibility is significant because most analytical reactions occur in aqueous conditions.…”

A Facile Electrosynthesis of Terephthalate (tp)‐Based Metal‐Organic Framework, Ni3(OH)2(H2O)2(tp)2 with Superior Catalytic Activity for Hydrogen Evolution Reaction

“…Previous works illustrate the electrosynthesis of MOF is associated with the reduction of proton in the solution and the generation of H 2 bub-ble. [22,23] Proton reduction from a solution of Et 3 NHCl in DMF for the cathodic electrodeposition of carboxylate-based MOF occurred at approximately -1.05 V. [23] Therefore, in the present work, with the deprotonation of terephthalic acid (H 2 tp -2e -= tp 2-+ H 2 ) at the negative potential during the electrosynthesis, the deprotonated ligand was coordinated with metal ion to form Ni-tp MOF and thus deposited on Ni foam. On the other hand, due to the proton reduction, hydrogen evolution reaction (2H + + 2e -= H 2 ) was inevitable, therefore, the concentration of OHin the neigboring local region was relatively higher, which can account for the OHsource in the formula of Ni…”