Plasmonic Ag/N-doped Graphene Nanoflakes as Electrocatalyst for Oxygen Reduction Reaction Enhanced by Solar Energy

Abstract

Plasmonic Ag nanoparticles have strong spectral absorption in ultraviolet and visible light due to unique localized surface plasmon resonance effects. Meanwhile, nitrogen-doped graphene (NG) incorporates nitrogen (N) atoms into graphene lattice through a hydrothermal process, thereby providing active oxygen reduction reaction (ORR) sites. Herein, N-doped graphene decorated with plasmonic Ag nanoparticles (Ag/NG) is synthesized and utilized as ORR catalyst. The ORR performance of Ag/NG greatly exceeds that of pure NG. Its half-wave potential is 0.86 V, exceeding that of commercial Pt/C (0.83 V). Under the AM 1.5G simulated sunlight, Ag/NG demonstrates photo-enhanced electrocatalytic performance with right shifting of onset potential and half-wave potential. In this case, the half-wave potential increases by 10 mV, while the current density also rises significantly. Therefore, the Ag/NG composite provides a potential strategy for the development of solar-enhanced electrocatalysts for fuel cells and metal-air batteries.