Enhancing Photocatalytic C–O Bond Cleavage in Ligning Using CuAlS₂/ZnS Quantum Dots: Synthesis Purification and Modification of Semiconductor Nanoparticles
T. Fay Harris, Gabi Vazquez
Department of Chemistry & Biochemistry
Faculty Supervisor: Michael Enright
This study explores type II semiconductor nanoparticles, specifically CuAlS₂/ZnS quantum dots (QDs), as photo redox catalysts for selective C-O bond cleavage on lignin model substrates. These materials offer an eco-friendly and low-cost alternative to conventional, environmentally hazardous or expensive catalysts typically used for solar energy and biomass valorization. CuAlS₂/ZnS QDs are promising catalysts for breaking down biomass due to its high redox potential that may allow for selective biomass decomposition without any pre-treatment, a requirement in all other selective biomass deconstruction pathways. One major obstacle to using CuAlS₂/ZnS QDs are the native oleic acid ligands capping these nanomaterials limit their solubility in polar solvents needed to drive our desired reactions. To address this, we are investigating ligand exchange with polar based ligands to enhance solubility, improve substrate compatibility, and boost catalytic performance. By optimizing ligand exchange protocols, this work advances the green chemistry potential of CuAlS₂/ZnS, contributing to the reduction of the carbon footprint by seeking to reduce our reliance on oil for carbon feedstocks. Additionally, we investigate the synthesis of CuAlS₂/ZnS QDs to determine specific methods to control the growth of these particles to form different shapes and size. We hypothesize that these advancements in synthesis and ligand exchange will allow for an increase in yield for high value small molecules, advancing green chemistry, and helping in the fight against climate change.