Metal-organic frameworks based nanostructure platforms for chemo-resistive sensing of gases

Metal-organic Frameworks (MOFs) are a category of porous crystalline structural materials wherein metal ions or clusters are connected by an organic ligand also known as "strut" or "linker". The largescale diversity of metal ions and organic linkers have allowed for the infinite number of possible metal linker combinations along with their ability to form conducting composites. However, their intrinsic defect such as poor conductivity has greatly impeded their full potential, especially in the electronic applications. Hence, MOF based composites and MOF derived nanostructures are being developed with the motive to incorporate advantageous attributes and to compensate the weakness of the individual components. Thus, MOF nanostructures are opening the door for their use for unique and attractive features in wide variety of applications such as sensing (Heavy metals, VOCs, microorganisms), gas storage (H-2, CH4), catalysis, optoelectronics and drug delivery etc. Many of these composite materials have been recognized as sensing layer material for the development of high-performance chemo-resistive gas sensors owing to the synergistic effects between them. Herein, the present article presents a critical review on the advancements in sensing performance of MOF and its nanostructures in terms of sensitivity, selectivity, reversibility, stability, shelf life and response and recovery time. (C) 2021 Elsevier B.V. All rights reserved.