Research

We are hybrid materials group focused on Optoelectronic and Catalytic Properties of Porous Molecular Assemblies. For green and sustainable energy resources, new directions are required for efficient light-harvesting (LH) and various energy converting processes. Considering ever growing carbon foot print, it is better to devise strategies to transform these molecules into usable chemical (fuels) instead of capturing and sequestrating (e.g. CCS). Our research aims to design materials with optimum absorbance and excited state properties for better LH systems. Likewise, we also aim to improve catalytic stability; improve turnover, and kinetics; and lower over-potentials for photo-, electro-, and chemical conversion processes. Currently we rely on designing, developing, and optimizing porous materials including coordination polymers, metal-organic frameworks (MOFs), and their hierarchical assemblies possessing modular chemical and electronic properties for such applications. In the long run, we like to gain control over the structure-dependent photophysical and electronic properties to establish soft materials for solar energy generation and storage.

Photophysics of self-assembled porous materials: The overarching goal here is to develop porous materials with unique optoelectronic properties based on the structural features as a function of their topology. In other words, topology controls the inter-linker orientation that defines transition dipole interactions of the chromophoric building block. One major thrust will be to develop a MOF-based LH-models. With appropriate chromophore symmetry and optimum inter-chromophoric interactions within MOFs, we want to control optical band gap, excited state lifetime, and exciton migration lengths. Since the chromophoric linkers, within MOFs, are positioned periodically around pores of varying sizes, these systems are fundamentally different than any solid state composition consisting of stacked aromatic chromophores that are infested with many un-useful exciton quenching pathways critical for efficient photon absorption.

Electrochemistry and porous electrocatalysts: Electrochemistry of porous materials are very interesting: the pores not only provide micro-cavity with controllable ions diffusions (hence kinetically controlled electrochemistry), but also facilitate synergistic role by various building units. We aim to modulate topological positioning of redox active linkers for multi-electron redox processes required for small molecule activations. Another area of thrust will be given to improve conductivity in this porous materials to aid their electrocatalytic activity.

 

Catalysis within pore: MOFs can be efficient heterogeneous catalyst as these easily recyclable frameworks provide stability for the reactive transition state(s). Besides, we plan to exploit proximal positioning of redox active linkers primed activating reagents where the pores can bind and or activate the substrate. Thus combination of topological diversity and the ability to installing auxiliary functionality will be explore. This will enable MOFs to establish pore chemistry primed for one or more reactive pathways that otherwise are impossible to achieve without enzymes.