RESEARCH PROJECTS
LIGAND DESIGN AND CATALYST SYNTHESIS
This project focuses on developing new earth-abundant metal-based molecular catalysts for CO2 and proton reduction, N2 activation and C-H oxidation by taking inspiration from natural enzymatic systems. Our approach involves introduction of proton responsive redox-active group in the ligand framework to facilitate multistep proton coupled electron transfer (PCET) reactions. For CO2 reduction, macrocyclic ligand platforms such as porphyrins, phthalocyanines, cyclams and dithiolenes are of particular interest due to their non-innocence and suitability to be used as building blocks for porous polymers.
"Molecular cobalt complexes with pendant amines for selective electrocatalytic reduction of carbon dioxide to formic acid", J. Am. Chem. Soc., 2017, 139, 3685–3696 (link)
"Catalytic hydrogen evolution by Fe(II) carbonyls featuring a dithiolate and a chelating phosphine", Inorg. Chem., 2014, 53, 8919–8929 (link)
CATALYST IMMOBILIZATION AND HYBRID MATERIALS
This project focuses on immobilization of molecular catalysts on semiconducting nanoparticles and porous materials (MOFs and COFs) for photocatalysis and photoelectrocatlysis. Depending on the nature of the nanoparticle surface, different anchoring strategies are explored which include: phosphonates on metal-oxide surfaces, in-situ polymerization, pyridine-to-metal-coordination, click reactions, and amide coupling. The designed hybrid catalysts will target CO2 reduction in colloidal suspension systems and photoelectolysers that couples the reductive chemistry with sustainable oxidation reactions.
"Light driven CO2 reduction by mesoporous carbon nitride modified with polymeric cobalt phthalocyanine", Angew. Chem. Int. Ed., 2019, 58, 12180–12184 (link)
"Light-driven hydrogen evolution catalyzed by a cobaloxime catalyst incorporated in a MIL-101(Cr) metal–organic framework", Sustainable Energy Fuels, 2018, 2, 1148–1152 (link)
POROUS MATERIALS, METAL ORGANIC FRAMEWORKS
The scope of porous materials is massive in the field of redox catalysis (light or electricity driven), however their application in the field is primarily limited by poor charge-transport behaviour in these materials. We aim to address it by using molecular catalysts and redox-active organic linkers to enable electron-hopping from linker-to-linker. Influence of secondary interactions (proton shuttle, hydrophobicity) are probed by modification of the pore structure of MOFs. We are also interested in exploring molecular dyes as linkers to yield light-harvesting materials where the porous framework will enable high-density and orderly distribution of the dyes.
"Molecular cobalt complexes with pendant amines for selective electrocatalytic reduction of carbon dioxide to formic acid", J. Am. Chem. Soc., 2017, 139, 3685–3696 (link)
"Catalytic hydrogen evolution by Fe(II) carbonyls featuring a dithiolate and a chelating phosphine", Inorg. Chem., 2014, 53, 8919–8929 (link)
POROUS POLYMERS AND HYBRID (PHOTO)ELECTRODES
Interfacing porous polymers with electrodes is a key challenge for their electrochemical application. This project focuses on directly growing the porous polymers as thin-films on diffent substrates including transparent metal-oxides, mesoporous electrodes (TiO2 and ITO), carbon-fibres and carbon-nanotubes. To provide better ‘wiring’ at the porous-polymer/electrode interface, different approaches for deposition and growth films will be investigated: direct growth under solvothermal condition, layer-by-layer assembly, and electropoylemrization.
