Since the increase in atmospheric CO2 levels has been identified as a major contributor to global warming, developing new technologies to mitigate CO2 emissions is imperative. Direct solar-driven conversion of CO2 to carbonaceous feedstock chemicals is a key target towards a carbon-neutral economy that allows mitigation of CO2 emissions and simultaneous storage of solar energy. Currently known photocatalysts for this purpose are not viable for practical application because they are either based on scarce, expensive and highly toxic materials, operate only in organic solvents or show low stability.
We are studying hybrid materials that combine the photophysical properties of nanomaterials with the high catalytic activity and selectivity of molecular catalysts. We are developing photocatalysts that are based on earth-abundant materials and active in water.
We are studying entirely precious metal-free catalyst systems for selective CO2 reduction in water, based on ahybrid design that combines the photo-physical properties of semiconductor nanocrystals with the selectivity of well-defined molecular catalysts based on nickel, cobalt and manganese. Designing suitable surface anchors allows us to attach these catalysts to CdS quantum dots to drive CO2 reduction with visible light. A second- generation system uses more benign ZnSe nanocrystals with much improved activity and efficient co-generation of H2 in the ideal syngas stoichiometry.
We are currently aiming to develop new immobilisation strategies based on supramolecular interactions between surface-modified nanomaterials and complementary anchors on suitably designed molecular catalysts