Grant: Discovery Grants Program - Individual

Plasmonic nanomaterials can strongly couple with light of appropriate energy and convert it into heat, a phenomenon known as the photothermal effect. The heat is localized around the plasmonic structure which yields high spatial precision and can be used to drive thermal processes without an external heat source. Nanostructured metals are currently the most widely explored class of plasmonic materials, but low melting points limit their utility in driving high temperature processes. Refractory materials can withstand high temperatures without significantly deforming or softening due to their high melting points. Therefore, the development of thermally and chemically robust refractory plasmonic materials will create exciting opportunities to explore photothermally driven reactions. Our proposed work will focus on the development of group V and VI plasmonic transition metal nitride and carbide nanostructures and group IV alloyed ternary nitrides. The nanostructures will be synthesized using solid-state, molten salt and/or microwave-assisted solution phase methods. The reaction mechanism will be investigated using in-situ X-ray diffraction and absorption experiments to better understand synthesis-structure-function relationships. The optical and photothermal properties, along with long-term chemical and thermal stability of the materials, will be established in detail. Refractory plasmonic materials that exhibit high light-to-heat conversion efficiencies will be used for the degradation of per- and polyfluorinated alkyl substances (PFAS) and methane activation. PFAS have been identified as emerging contaminants by Environment Canada while methane is a potent greenhouse gas, and both are very stable and difficult to chemically activate. A photothermal reactor built in-house will be used to react PFAS with silanes to generate hydrogenated molecules and convert methane to heavier hydrocarbons. The field of refractory plasmonics is still in its infancy, but Canadian scientists have an opportunity to lead the way in this area. The proposed work will help develop synthetic tools to make an entire class of next-generation refractory plasmonic nanomaterials composed of non-precious metals. Degradation/activation of environmental pollutants such as PFAS and greenhouse gases such as methane are among Canada's top priorities. Using inexpensive elements and freely available solar energy to realize these goals will make the required chemical processes significantly greener. Due to the interdisciplinary nature of this work, the trainees working on these projects will acquire skills and expertise across many disciplines including chemistry, physics, and engineering. Canada will benefit from a pipeline of highly trained workers that can address complex and interdisciplinary challenges associated with the transition to a low carbon economy.