Bulk-Processed Pd Nanocube – Poly(methyl methacrylate) Nanocomposites as Plasmonic Plastics for Hydrogen Sensing

Nanoplasmonic hydrogen sensors are predicted to play a key role in safety systems of the emerging hydrogen economy. Pd nanoparticles are the active material of choice for sensor prototype development due to their ability to form a hydride at ambient conditions, which creates the optical contrast. Here, we introduce plasmonic hydrogen sensors made from a thermoplastic nanocomposite material, that is, a bulk material that can be moulded with standard plastic processing techniques, such as extrusion and 3D printing, while at the same time being functionalized at the nanoscale. Specifically, our plasmonic plastic is comprised of hydrogen-sensitive and plasmonically active Pd nanocubes mixed with a poly(methyl methacrylate) matrix, and we optimize it by characterization from the atomic to the macroscopic level. We demonstrate melt-processed deactivation resistant plasmonic hydrogen sensors, which retain full functionality even after 50 weeks. In a wider perspective, we advertise plasmonic plastic nanocomposite materials for application in a multitude of active plasmonic technologies since they provide efficient scalable processing and almost endless functional materials design opportunities via tailored polymer – colloidal nanocrystal combinations.