Reversible Enlargement of Photoswitchable Dielectric Properties by Plasmonic [60]Fullerenyl Core–Shell Nanoparticles on Graphene Nanosheets

Abstract

Utilization of [60]­fullerosome monolayer grafting approach on both sides of graphene nanosheets giving the corresponding sandwiched nanostructures was demonstrated as a key intermediate for the construction of photoswitchable and tunable dielectric graphene nanosheet materials. They were covered by magnetic plasmonic core–shell nanoparticles of γ-FeO x @AuNP and light-harvesting C60(>DPAF-C9) monoadduct conjugates as the shell layer via a subsequent deposition procedure. Resulting multilayered core–shell nanosheet materials were found to be capable of inducing reversible dielectric property amplification effects in a photoswitching manner in the radio frequency (RF) range of 1.0–18 GHz. They were also found to be RF-wave-absorbing materials that led to the observation of minimum reflection coefficient values (low −dB). We substantiated these photophysical properties by relative dielectric (εr′) measurements and related applications using a combination of bistatic angle (θ)-, frequency-, and irradiation-time-dependent measurements. Specifically, we investigated the photoinduced changes of relative dielectric characteristics as a result of accumulated surface plasmon resonance (SPR) energy at the core–shell interlayers in a nanoscale toward potential morphological modulation of RF signals by photoswitching tunability of reflectivity.