RUI: Chemical and photophysical interactions between colloidal quantum dots and transition metal catalysts used for photocatalytic CO2 reduction

Amherst College, Amherst MA

Investigators

Abstract

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Jacob Olshansky of Amherst College is studying the interactions between nanocrystalline light absorbers and metal catalysts for the photocatalytic conversion of carbon dioxide. Carbon dioxide is a promising carbon source since it is cheap and abundant and can be extracted from air or at combustion sources. Therefore, developing methods to catalyze the conversion of carbon dioxide to usable hydrocarbons is critically important. The current award focuses on employing light energy to catalyze carbon dioxide conversion into compounds that can readily be transformed into a wide range of useful hydrocarbons. A relatively new class of hybrid materials will be employed, consisting of nanoparticles and catalysts composed of earth-abundant materials. Experiments will focus on understanding the interactions between the nanoparticles and catalysts with an eye towards developing highly efficient hybrid photocatalysts. The investigations will involve undergraduate students in cutting-edge research that is both interdisciplinary and highly collaborative. With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Jacob Olshansky of Amherst College is studying the chemical and photophysical interactions between colloidal quantum dots and transition metal catalysts used for photocatalytic carbon dioxide reduction. Quantum dots are relatively robust and offer size- and composition-tunable light absorption properties. Furthermore, as nanoparticles, they possess high surface areas for performing chemical conversions. Therefore, they are promising not only as light absorbers for photocatalysis but also as highly tunable systems. The current award will leverage this tunability to map out geometry- and composition-dependent photoexcited charge transfer dynamics to understand photocatalysis. Well-defined compounds known to catalyze carbon dioxide reduction as well as ill-defined metal ion catalysts will be employed. Concurrently, a new class of visible light-absorbing quantum dots for reductive photocatalysis will be developed by preparing alloyed zinc selenide and zinc telluride quantum dots insulated with a zinc sulfide shell. These quantum dot structures will not only provide novel platforms for photocatalysis but will also allow us to map out relationships between energetics or distance and charge separation rates. Addressing these fundamental photophysical questions will be made possible through ultrafast transient absorption spectroscopy, provided by a network of collaborators. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.