(593f) Laser Ablation Synthesis in Solution for the Rational Design of Hybrid Carbon-Based Nanocomposites for Enhancements in Electrochemical Storage and Conversion Systems

Ribeiro, E. L. - Presenter, University of Tennessee, Knoxville
Khomami, B., University of Tennessee
Mukherjee, D., University of Tennessee
Hu, S., University of Tennessee, Knoxville
The increasing global demand for clean and sustainable energy sources has given rise to the significant interest in the rational synthesis and design of low-cost and efficient functional nanocomposites and nanomaterials as catalyst and/or supercapacitors in advanced electrochemical energy storage/conversion systems. Nonetheless, the design of such nanomaterials with tailored interfacial functionality and charge transport properties relies on systematic and fundamental understanding of the processing-structure-property relations for precise tailoring of architectures and compositions of the active nanomaterials without using any undesired chemicals/surfactants/ligands that can compromise their electrochemical performance and interfacial activities . Herein, we present our most recent findings in using Laser Ablation Synthesis in Solution (LASiS) as a strategy and pathway for the facile and environment-friendly, yet efficient, synthesis of new classes of carbon-based hybrid nanocomposites (HNCs) decorated with metal-oxide nanoparticles (NPs) that exhibit unique electrocatalytic and supercapacitive properties. Initially, we report the use of LASiS coupled with two-post treatments for the fabrication of (1) Co3O4 NPs/reduced graphene oxide (rGO), (2) Co3O4 nanorods (NR)/rGO, and (3) Co3O4 NPs/nitrogen-doped graphene oxide (NGO). This methodology allows us to tune the selective functionalities of the HNC by adjusting their structure-property relationships. The Nitrogen doping in the NP/NGO HNC, for instance, promotes a higher electron conductivity while enhancing the electrochemical activity and preventing the aggregation between NPs. These interfacial energetics and arrangements have indicated to yield superior Oxygen Reduction Reaction (ORR) electrocatalytic activities. Similarly, the NR/rGO HNCs present a network of interconnecting 1D nanostructures that give rise to an effective charge transport and electrolyte diffusion at the electrode-electrolyte interfaces, resulting in the enhancement of the supercapacitive properties. On the other hand, the NP/rGO HNCs demonstrated intermediate functionalities towards both ORR catalysis and supercapacitance.