Laser-Induced Graphene-Palladium Nanohybrids for Flexible and Wearable Gas Sensor

P. Kang, B.G. Kim, M. Kim
George Mason University,
United States

Keywords: graphene, nanoparticle, quantum materials, laser manufacturing, sensing


Hydrogen, as a renewable energy source, has garnered substantial interest due to its abundance, high energy content, and clean combustion profile. However, effective hydrogen gas leakage detection systems are imperative to mitigate potential explosion risks associated with hydrogen storage or generation. Carbon nanomaterials, including carbon nanotubes, graphene, and carbon nanofibers, have demonstrated promise for electrochemical hydrogen detection due to their superior mechanical and chemical properties. We introduce a unique and fast photothermochemical single-step processing method utilizing an infrared laser and polymers derived from carbon and palladium precursors [1]. Our approach involves synthesizing a nanoassembly of palladium nanoparticles (Pd-NPs) and porous graphene concurrently. Polymers of intrinsic microporosity (PIM-1) are employed as precursors due to their ability to yield aromatic polybenzodioxane structures with cyano groups, facilitating the formation of porous graphene. The process involves the use of PIM-1/Pd acetate polymers as precursors, followed by pyrolysis and photolysis to synthesize carbon-encapsulated Pd nanoparticles in porous graphene. A CO2 laser is employed to irradiate the polymer films, inducing a photothermal and photochemical hybrid nanoassembly of 3D porous graphene and Pd-NPs. The simultaneous occurrence of photothermal processes and photon-induced thermal and non-thermal chemical reactions results in the formation of a nanohybrid material exhibiting outstanding crystallinity, structural homogeneity, and a large surface area with a hierarchical pore structure. The nanohybrid material demonstrates exceptional mechanical robustness, high electrical conductivity, electrochemical reliability, and reversible reactivity with hydrogen. Notably, the material exhibits ultrasensitive, repeatable, and stable hydrogen sensing even under various mechanical strains such as bending and twisting. This exceptional flexibility positions the nanohybrid for applications in wearable technologies, particularly in next-generation flexible gas and electrochemical sensor systems. The laser-induced graphene-palladium nanoparticle nanohybrid presents a scalable and fast method for synthesizing flexible and wearable hydrogen sensors, addressing the challenges posed by complicated fabrication processes in existing methods. The study underscores the potential of this nanohybrid material in advancing the field of hydrogen sensing, offering a robust and versatile platform for applications in various emerging technologies.