Encapsulation of graphene oxide/metal hybrids in nanostructured sol–gel silica ORMOSIL matrices and its applications in optical limiting

Abstract

Abstract Optically transparent organically modified silica (ORMOSIL) gel glasses doped with graphene oxide (GO)/metal nanoparticle (NP) hybrids were synthesized using a simple sol–gel technique. The two-dimensional GO/metal NP hybrids dramatically changed the surface characteristics of silica-based gel glasses whilst maintaining their structural integrity during the sol–gel procedure. The optical limiting (OL) properties of GO/metal NP-doped ORMOSIL gel glasses were investigated using a nanosecond open-aperture Z-scan technique at 532 nm. The metal NP hybrids exhibited significantly enhanced OL performance compared with their individual counterparts in ORMOSIL gel glasses. The improvement in GO/Au NP-doped gel glasses is attributed to surface plasmon resonance, while interband transition is responsible for the enhancement in GO/Pd NP-doped gel glasses. The OL behavior of GO/metal NP-doped gel glasses were mostly attributed to the combined mechanisms of excited state absorption and nonlinear scattering.