Currently, improvements in the durability, performance and manufacturing cost of nanoparticle arrangements are central to advancing technologies like proton exchange membrane fuel cells (PEMFCs) and sensors. Some research projects in our group involve new approaches for synthesizing PEMFC catalysts and composites for Raman-based detection. We aim to utilize copolymer films and latexes to template the synthesis of mono- and bimetallic nanoparticles (NP) that are active as catalysts for fuel cells or as surface-enhanced Raman scattering (SERS) materials. The work explores the underlying principles for prescribing the size, spacing and composition of NPs isolated from self-assembled nanostructures of copolymers loaded with metallic ions or metal NPs. We often aim to understand any structure-property relationships with the polymer template. Detailed catalytic activities or SERS-activities are elucidated and considered in relation to the definition of the polymer structure and it's length scale.
In another project, we aimed to establish a versatile route for tethering catalytically active nanoparticles onto surfaces that are relevant for fuel cells. Our initial phase has shown that polyethyleneimine (PEI) stabilized platinum nanoparticles (Pt NPs) can be electrostatically bonded to the charged conducting polymer PEDOT:PSS. This permits a layer-by-layer (LbL) deposition strategy that can grow thin films containing these materials (see green layer in image). Importantly, we have found that the embedded Pt NPs are electrochemically accessible and can catalyze the oxidation of methanol fuel - a requirement for the direct methanol fuel cell. The ability of the LbL deposition technique allows for nanometer length scale tuning of the catalysts layer thickness and hence catalytic activity. Current work is focused on the extension of the deposition strategy to low precious metal content multi-metallic nanoparticles.
See our paper in: Chemistry of Materials.
See our paper in: Journal of Materials Chemistry A.
See our paper in: ACS Omega.
See our paper in: ACS Applied Materials and Interfaces.