In Prof. Ira A. Weinstock’s laboratory, 1 to 3 nm sized metal oxygen cluster anions (polyoxometalates, or POMs) are used as well defined molecular and supramolecular catalysts and as components (building blocks and templates) for the self-assembly of functional nanostructures. Many POMs, typically prepared from early-transition metals (e.g., V, Mo, and W), possess extensive and reversible redox chemistries, and as a class, their compositions and structures, which control and impart functionality, can be rationally modified at the atomic level. Functional molecular systems are obtained by incorporating reactive transition-metal cations, and by using the interiors of larger POM “capsules” as nano-scale domains for reactions under confined conditions. POM clusters are also used to control the nucleation, growth and stabilities of reactive, binary-element nanocrystals. By incorporating tailored counter-cations, POMs can additionally serve as functional building blocks for the electrostatic self-assembly of reactive monolayers on metallic nano-structures. These multi-component "nano-reactors" are being designed to provide visible-light driven photocatalytic systems for water splitting, including the coupling of water oxidation to CO2 reduction. These targets sum to the use of sunlight, water and CO2—just as in photosynthesis—to generate H2 and CO, feedstocks for the industrial-scale production of renewable liquid fuels.
Dr. Taleb Mokari's group studies nanomaterials at all stages of their lifecycle, from design to application to environmental impact. These nanomaterials possess properties intermediate between bulk materials and molecules. The tunability of their properties, including optical and electrical, allow for a range of potential applications. The applications our group focuses on are catalysis and solar energy conversion from nanomaterial composite systems. As catalysts, nanomaterials could improve product selectivity, thereby reducing chemical waste and produce cleaner fuels. As energy conversion materials, they could lower the final cost per kWh to the end user. From precursor design to impact on the environment, the lab examines the possible contributions nanomaterials could have on our world.
Dr. Maya Bar-Sadan’s research addresses success-limiting fundamental problems by using cutting-edge transmission electron microscopy (TEM) to elucidate correlations between the atomic structure and physical properties at the interfaces within functional devices on the single-particle scale.
Specifically, the research will combine atomic resolution imaging with low-loss electron energy loss spectroscopy (EELS) in an aberration-corrected scanning transmission electron microscope (STEM) to probe the plasmon response of metallic nanoparticle catalysts. In addition, the understanding of the synergistic effect in hybrid structures (such as semiconductor core-shell particles, and semiconductor-metal nanorods, which are proposed for photocatalytic processes) requires correlation of the physical properties with the rearrangement of atoms and charges around the interface and the mapping of their optical response.