Research
The world today stands
at a pivotal crossroads, where the rapid development of smart materials is met
with the pressing challenges of global warming and the energy crisis. At MolMat
Lab, we are dedicated to addressing these critical issues through the design
and synthesis of inorganic-organic hybrid materials, including metal-organic
frameworks (MOFs) in both bulk and nanoscopic forms, coordination polymer gel
(CPG), as well as porous organic polymers (POPs). With a comprehensive
synthetic toolkit, our group has made notable contributions to the field of
porous and soft materials, exploring their potential for various renewable
energy and environmental applications.
Classes of materials that we look into:
- Apart from synthesis, structure-property relationships and applications of bulk MOFs,we also work on nanoscale MOFs. Our group has made significant contributions to advancing the concept of post-synthetic modification of MOFs through metal ion or linker exchange, as well as guest encapsulation. Such works aim to develop materials with high surface areas and tuneable porosities to enhance effectivity in multifarious applications like catalysis, gas storage and separation.
Our group also investigates
functional organic porous polymers, particularly focusing on Covalent Organic
Frameworks (COFs) and Conjugated Microporous Polymers (CMPs). Post-synthetic
modification of these materials have also been carried out by metal ion
chelation. These materials have been explored for intriguing photocatalysis,
electrocatalysis, gas storage and separation, and sensing applications.
Our research extends to the
development of nanocomposite materials by integrating different types of
functional materials like, MOFs and COFs, with other nanostructures like 2D
graphene oxide, MoS2 and amino-clay. These materials are
investigated for their potential in gas storage, separation, and catalytic
applications.
Coordination polymer gels
(CPGs) are soft, processable materials combining organic and inorganic
components. Based on the coordination-driven supramolecular interactions,
different types of nano-morphologies have been realized. These materials are
studied for their unique optical and electronic properties, contributing to the
development of advanced functional materials. These materials are explored for
diverse applications, including photoreduction of CO₂, sensing, and information
decoding through photochromic properties.
Carbon Capture & Conversion
CO2 capture and conversion are crucial for mitigating climate change by reducing greenhouse gas emissions while transforming captured carbon into valuable fuels, for a sustainable circular economy. Our group has judiciously designed framework structures by incorporating polar functional groups like -F, -OH, -NH2 on the pore surface which can effectively interact with the quadrupolar CO2 molecules and subsequently affect the adsorption selectivity. Our group has shown hydrophobic MOFs based on fluorinated linkers are more effective in selective capture of CO2 which is of paramount importance for separation of CO2 from flue gas mixture. Taking a step further to efficiently convert CO2 into valuable feedstock, enabling sustainable chemical transformations, our research group have unveiled a number of photocatalytic strategies by harnessing solar energy. This has been accomplished through various approaches: (i) Tuning the pristine MOF/POP/CPG catalyst structure at the molecular level, (ii) Introduction of molecular catalysts in the framework by post-synthetic modification or guest encapsulation and (iii) Heterostructure formation of MOF/POP/CPG with other functional materials for efficient photochemical CO2 reduction. In numerous instances, the catalysts operate with exceptional efficiency in pure aqueous media, closely emulating the natural photosynthetic process.
(Related publications from the group: Chem. Sci., 2025, 16, 3646-3654, Angew. Chem. Int.
Ed. 2024, 63, e202315596, Chem.
Sci., 2024,15,
7698-7706, Adv. Funct. Mater. 2024, 34, 2407721, Chem. Sci., 2024, 15, 16259-16270)
Electrochemical Energy Conversion and Storage
Electrochemical energy
storage and conversion are paramount to advancing sustainable energy solutions,
enabling efficient power management, and accelerating the global transition
towards renewable energy technologies. Oxygen reduction reaction (ORR), oxygen evolution
reaction (OER), and hydrogen evolution reaction (HER) are crucial
electrochemical reactions that drive the efficiency of fuel cells and metal-air
batteries. Our research group have developed novel electrochemically active
CMPs by linking donor nodes and acceptor spacers which showed impressive oxygen
reduction reaction ORR activity and catalytic stability over time. We have also
developed MOF-derived trifunctional ORR, OER, and HER electrocatalysts and studied
its application in a Zn–air battery. Apart from these, the group has also
designed and developed COF-based efficient electrocatalysts for electrochemical
CO2 reduction to C2 liquid products such as ethanol. Dr.
Maji’s team has also developed versatile materials capable of functioning as
both a photoanode and a dark cathode in a photoelectrochemical (PEC) cell,
effectively driving artificial photosynthesis. In a recent breakthrough, they
have been able to mimic ion transport in natural cells to achieve efficient ion
gating in MOF nanochannels and have employed these properties to study ion
conduction in these systems.
(Related publications from the group: Adv. Energy
Mater. 2025, 2404976, Energy
Environ. Sci., 2024,17,
2315-2325, J. Mater. Chem. A,
2024,12, 13266-13272, ChemSusChem
2025, e202402325, Small 2024, 20, 2406173, J. Am. Chem. Soc.
2023, 145, 27103–27112)
Green H2 production
Hydrogen (H₂) evolution through water reduction is a sustainable process to generate green, renewable H2 fuel. Our group has worked towards the design and development of MOFs/POPs/CPGs for the development of high-functioning photocatalysts for H2 production. We have showed that bandgap engineering in donor-acceptor frameworks is a potential way to increase the solar-energy harvesting towards photochemical water splitting. In other cases, modulating the photosensitizing and catalytic sites of these materials by nanoparticle encapsulation or co-catalyst integration are also effective strategies to achieve efficient H2 yields. In a recent groundbreaking advancement, our team have engineered a donor-acceptor-based ferrielectric COF piezocatalyst, capable of exclusively harnessing mechanical energy for sustainable green hydrogen production.
(Related publications from the group: Adv. Funct. Mater. 2025, 2502787, ACS Appl. Mater. Interfaces 2023, 15, 21, 25173–25183, ACS Appl. Mater. Interfaces 2022, 14, 25220–25231, Nat. Commun., 2021, 12, 7313, J. Mater. Chem. A, 2021,9, 13608-13614, Chem. Eur. J. 2019, 25, 3867).
Adsorptive based Separation
Adsorptive-based technologies play a crucial role in efficient
separation, purification, and environmental remediation by selectively
capturing and removing contaminants or valuable molecules from complex
mixtures. Our team has made remarkable advancements in the selective separation
of aromatic isomers from complex mixtures employing a flexible porous
coordination polymer. We were able to establish a selectivity order among the
geometrical isomers of halobenzene series. Additionally, small hydrocarbons C2H2 (acetylene),
C2H4 (ethylene), C2H6 (ethane), C3H6
(propene) and C3H8 (propane) are very important chemical
feedstock for many industrially important materials. By exploiting the
different adsorption enthalpy of olefin and paraffin toward functionalized pore
surface or by tuning the channel window size of the MOF materials, our group
has demonstrated separation and purification of different hydrocarbons at
ambient conditions.
(Related Publication from the group: Chem. Sci., 2023, 14, 12321-12330, Chem. Sci., 2022,13, 7172-7180, Angew. Chem. Int. Ed.,
2021, 60, 19921, ACS Omega 2018, 3, 2018–2026, Chem. Eur. J., 2016, 22, 6059, This work has been highlighted in
Atlas of Science https://atlasofscience.org/; Chem. Commun., 2017, 53, 4907)
Optoelectronics
Optoelectronics are essential for advancing modern technology, enabling
efficient light-based communication, sensing, and molecular recognition. Photo-luminescence
properties in MOFs can be realized based on metal ions (like Lanthanide ions)
or from the chromophoric linkers. The group have been systematically working on
tunable emission of MOFs by adopting both approaches. Tunable emissions
including white light emission in MOFs have been realized by doping EuIII
in TbIII MOFs by FRET processes. Emission can be realized and tuned
by the guest molecules in the MOFs. It is also possible to get specific
emissive responses in these MOFs via charge-transfer (CT) complexation. We have extensively designed a number of MOF/POP based
luminescent sensors for the detection of cations and anions either by
fluorescence ‘turn on’ or ‘turn off’ mechanisms. Furthermore, the range
of analytes have been extended to solvents impurities like water in organic
solvents as well as minute variations in temperature. The group has also been
actively involved in the development of photo-switching emission of
photochromic materials for intriguing applications such as synthesis of
security inks.
(Related publications from the group: J. Mater. Chem. C, 2022, 10, 7558-7566, ACS Appl. Mater.
Interfaces 2022, 14, 49014–49025, Chem. Sci., 2021, 12, 2674, Chem. Eur. J., 2015, 21, 10799, Chem. Commun., 2015, 51, 9876, Chem. Commun., 2014, 50,
13567-13570)
Water harvesting
Expanding atmospheric water harvesting (AWH) beyond arid environments to settings with moderate indoor humidity and temperature is crucial for both commercialization and addressing the global freshwater crisis. Our group has developed a binary (aminopropyl-functionalized magnesium phyllosilicate or aminoclay, and MOF) and ternary (aminoclay, graphene oxide, and MOF) nanocomposites, highlighting their water storage and harvesting capabilities in indoor environments. Furthermore, we have explored the dynamics of water collection by varying ambient humidity, release temperature, and on-demand sorption/desorption cycles under typical indoor conditions without relying on solar irradiation.
(Related publications from the group: Adv. Funct. Mater. 2022, 32, 2203093)