Graphene oxide decorated nanoscale iron sulfide for highly efficient scavenging of hexavalent chromium from aqueous solutions

•FeS nanoparticles were effectively decorated onto the surface of GO.•The aggregation of nanoscale FeS decreased with enhanced reactivity.•The nanocomposites GO/FeS displayed an enhanced Cr(VI) sorption capacity.•Both surface sorption and reduction contributed to Cr(VI) removal by GO/FeS.