Photocatalytic activity of reduced graphene oxide/SnO2 nanocomposites prepared in ionic liquid

•RGO/SnO2 composite was efficiently prepared via a one-step method in ionic liquid.•Graphene sheets were coated uniformly with SnO2 nanoparticles with a size of ∼5 nm.•Nanocomposites exhibited much better photodegradation efficiency than bare SnO2.•This is a green route suitable for production of other graphene-metal oxide composites.

Reduced graphene oxide/SnO2 nanocomposites were synthesized within 10 min using a facile microwave-assisted method in an ionic liquid, a clean solvent, without any reducing reagent. The tetragonal structure of SnO2 was confirmed by X-ray diffraction. Field emission scanning electron microscopy and transmission electron microscopy showed that graphene sheets were coated uniformly with SnO2 nanoparticles with a small mean diameter of approximately 5 nm. X-ray photoelectron spectroscopy confirmed the removal of oxygenous functional groups from graphene oxide to graphene with the formation of SnO2 simultaneously. The photocatalytic activities of the as-prepared nanocomposites for the degradation of methylene blue under UV light irradiation were investigated. The nanocomposites exhibited better photodegradation efficiency than the bare SnO2 nanoparticles.