Tuning the Size and Shape of NanoMOFs via Templated Electrodeposition and Subsequent Electrochemical Oxidation

Abstract

The control over the size and shape of nanoMOFs is essential for their exploitation in integrated devices such as sensors, membranes for gas separation, photoelectrodes, etc. Here, we demonstrate the synthesis of nanowires and three-dimensionally interconnected nanowire networks of Cu-based metal−organic frameworks (MOFs) by a combination of ion-track technology and electrochemical methods. In particular, Cu nanowires and nanowire networks were electrodeposited inside polymeric etched ion-track membranes and subsequently converted by electrochemical oxidation into different Cu-based MOFs such as the wellknown Cu 3 (BTC) 2 (also known as HKUST-1) and the lesserknown MOF Cu(INA) 2 . The MOFs are formed inside the template, therefore adopting the shape of the host nanochannels. The synthesized MOF nanowires exhibit tunable diameters between 80 and 260 nm. Characterization by X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, scanning electron microscopy, and transmission electron microscopy indicates that the employed electrochemical conversion includes the formation of Cu 2 O as an intermediate, as well as the initial formation of an amorphous MOF phase, which crystallizes upon longer reaction times.

Recent Improvement Strategies on Metal-Organic Frameworks as Adsorbent, Catalyst, and Membrane for Wastewater Treatment

“…The electrochemical deposition (EDS) method was proposed by many works to overcome inhomogeneous of MOF formation prepared by in situ and secondary growth method [ 129 , 130 ]. The MOF membrane generated via the EDS method could be achieved by anodic dissolution and reductive deprotonation [ 131 ].…”

Metal–Organic Framework Based 1D Nanostructures and Their Superstructures: Synthesis, Microstructure, and Properties

“…Various organic templates were used to direct the synthesis of 1D tubular-structured MOFs. − ,− In addition to the template types, different deposition methods (solution-based deposition, electrodeposition, etc.) were used to coat the template with the MOF precursors.…”

“…In 2019, Caddeo and co-workers extended this approach by using an electrodeposition method to coat the PCTE template . 3D interconnected NW networks of Cu-based MOFs (i.e., HKUST-1 and Cu­(INA) 2 with INA = isonicotinic acid) were produced by combining PCTE templating and electrochemical methods .…”

“…The synthesized MOF NWs exhibit tunable diameters ranging between 80 and 260 nm, replicating the dimensions of the PCTE pore arrays. Moreover, the use of PCTE templates with three dimensionally interconnected nanochannels has led to the production of mechanically stable and 3D-ordered MOF NW networks that can be integrated into planar devices for sensing and photocatalysis applications . The use of biological templates for the formation of 1D MOF NTs and NWs is quite scarce despite their low toxicity, biocompatibility, and low cost.…”

“…44 In 2019, Caddeo and co-workers extended this approach by using an electrodeposition method to coat the PCTE template. 73 3D interconnected NW networks of Cu-based MOFs (i.e., HKUST-1 and Cu(INA) 2 with INA = isonicotinic acid) were produced by combining PCTE templating and electrochemical methods. 73 Cu NWs were first electrodeposited inside the PCTE membranes, followed by their subsequent conversion via electrochemical oxidation in a solution containing the required organic linker of each MOF.…”