Synthesis and Preparation of CuAlS2/ZnS for Photoredox Catalysis
Authors: Fay Harris, Gabriella Vasquez, Chloe Peak
Faculty Supervisor: Michael Enright
Department: Chemistry & Biochemistry
Based on our world’s growing global energy demands, it is important to develop new and improved sustainable energy solutions in order to reduce our CO2 footprint. Our approach is to use quantum dots to convert biomass into high-value small molecules using solar energy. Here, we seek to use CuAlS2/ZnS quantum dots as photoredox catalysts for cleaving C-O bonds in biomass model substrates. CuAlS2/ZnS is a promising photocatalyst due to its type II bandgap and its components are eco-friendly alternatives to environmentally hazardous chemicals commonly found in quantum dots. Presented here are synthetic, purification, and post-synthetic treatments of CuAlS2/ZnS. Monodisperse quantum dots with tunable core (CuAlS2) size and shell (ZnS) thicknesses are obtained by manipulating nanocrystal growth conditions. Furthermore, prior literature reports on CuAlS2/ZnS showed the particles had limited long-term stability. This work demonstrates purification improvements that yield higher-purity materials that remain dispersed for months. These outcomes also allow for new ligand exchange procedures, shown here, to bring the particles into solvents of different polarities and ultimately have the potential to facilitate high-performance photocatalysis.