WHAT WE DO with The FRAMEWORKS...
...Mainly with Metal Organic Frameworks (MOFs)
Due to Covid-19, the lab was closed from 24-Mar-2020 to 31-Mar-2021. The lab reopened in phases since 01-April-2021....
Gas Storage and Separation:
Metal-organic frameworks (MOFs) having an extensive class of crystalline materials with ultrahigh porosity (up to 90% free volume) and enormous internal surface areas, extending beyond 6000 m2/g with the extraordinary degree of variability for both the organic and inorganic components of their structures, claiming great interest towards potential applications in clean energy, most significantly as storage media for gases such as acetylene and methane, and as high-capacity adsorbents to meet various gas separation applications. We are actively working on these aspects particularly focusing on designing strategies on the water and/or moisture stability of the synthesized MOFs.
For example, We have synthesized microporous Co(II)-MOFs (IITKGP-6 and IITKGP-8) which revealed their potential toward high separation selectivity for CO2 over N2 and CH4 at ambient conditions (i.e. flue gas and biogas separations). They are water or moisture stable needed for practical implementations for CO2 capture and separation technology.
On the other hand, MOF IITKGP-20 showed excellent stability over a wide pH range with scalable preparation and exhibited its promise for efficient C2s over C1 hydrocarbon separations (i.e. separations of C2H2, C2H4 and C2H6 from CH4).
Proton conduction (PC) having the paramount property for biological organisms and energy conversion in electrochemical systems such as polymer electrolyte fuel cells, Nafion and Nafion-like polymer membranes are also efficient proton conductors; however, the high costs and temperature limitations have driven a number of strategies towards the design of alternative materials, such as coordination polymers (CPs) and/or metal-organic frameworks (MOFs) and covalent organic polymers (COFs).
For example, we have proposed a simple yet powerful template-assisted strategy for synthesizing proton conducting MOFs where the templates remained in the frameworks with charge assist proportions which shows exceptional proton conductivity in the order 10-1 Scm-1. This study reports one of the highest proton conductivity by MOFs thus far.
Luminescence & Sensing:
On account of the crucial role of metal ions in environmental and biological systems, the design and synthesis of metal-ion sensors have attracted considerable attention from researchers across the globe. Most important and essential elements such as Fe(III) in the human body, play vital functions in many biochemical processes. Similarly, the gradual gathering of Al(III) in human body with a high dose has the direct influence on the nervous system causing many symptoms of Al(III) toxicity for instance Alzheimer’s disease, Parkinson’s syndrome and osteoporosis. On the other hand, large amounts of toxic organic small molecules and hazardous heavy metal ions are released into the environment with serious adverse effects on the environment and human health. Thus, it is very important to develop novel systems that have the ability to detect exclusively desired ions and toxic small organic molecules like nitromethane by convenient methods that are easy to apply, such as luminescence quenching by exploiting the luminescence nature of MOFs.
For example, we have reported a porous Zn-MOF (IITKGP-9) which shows its potential to act as a trifunctional MOF capable of selectively adsorbing gas molecules, selectively sensing metal ions, and selectively detecting small organic pollutants.
In recent years, MOFs having well-defined crystal structures, modifiable pore topology, excellent tailorability, high surface areas have presented huge potential, especially in the field of heterogeneous catalysis. The catalytic property of MOFs can be readily controlled by the proper selection of metal ion and organic ligands. Based on the literature reports, there are different types of the active sites in the MOF which can catalyze the heterogeneous catalysis reactions (structural defect site, Lewis acid centre, open metal site and MOFs with a functional linker).
For example, two new 3D Co(II)-MOFs with Lewis acid-Lewis base bi-functionalities were successfully developed based on organic dicarboxylic acids and azo linked N,N' donor spacer which showed excellent heterogeneous catalytic behavior toward the cyanosilylation reactions and Knoevenagel condensation.
Metalo Hydrogen-Bonded Organic Frameworks (MHOFs):
Proton conductivity has long been investigated as a desirable property in a variety of materials, whether organic, inorganic or crystalline materials to construct proton exchange membranes (PEMs) for hydrogen fuel-cell applications. Among these, crystalline materials that include metal-organic frameworks (MOFs), coordination polymers (CPs), polyoxometalates (POMs), H-bonded organic frameworks (HOFs), and covalent organic frameworks (COFs) have attracted immense attention to the field of proton conducting materials, and have received great development in recent years.
The heart of the design and synthesis of new proton conducting crystalline materials is the thoughtful selection of reaction substrates. In order to search for new crystalline materials as super-protonic conductors, we explored for the first time metalo hydrogen-bonded organic frameworks (MHOFs) as a new class of promising conducting materials.