3D interlayer nanohybrids composed of reduced graphenescheme oxide/SnO2/PPy grown from expanded graphite for the detection of ultra-trace Cd2+, Cu2+, Hg2+ and Pb2+ ions

Abstract The three dimensional (3D) interlayer rGO/SnO 2 /PPy nanohybrids, based on reduced graphene oxide (rGO) obtained from expanded graphene (EG), SnO 2 nanoparticles (NPs) and polypyrrole (PPy) were obtained by facile method. The rGO/SnO 2 /PPy nanohybrid electrodes were composed of a thin conducting film of PPy on the surface of rGO/SnO 2 (EG: Sn molar ratio of 1.2:1), used for the determination of ultra-trace ions (Cd 2+ , Cu 2+ , Hg 2+ and Pb 2+ ) with the square wave anodic stripping voltammetry (SWASV) technique. Among the rGO/SnO 2 /PPy, rGO/SnO 2 (rGS), rGO/PPy (rGP) and pure polypyrrole (PPy) samples, the sensitivity and current density of rGO/SnO 2 /PPy-4 (rGS: PPy mass ratio of 1:4), have shown excellent performance for the recognition of above ultra-trace heavy metal ions (HMIs). The limit of detection (3σ method) of the rGO/SnO 2 /PPy-4 nanohybrids modified electrode toward Cd 2+ , Cu 2+ , Hg 2+ and Pb 2+ ions was 7.5 × 10 −13 , 8.3 × 10 −13 , 8.1 × 10 −13 and 8.8 × 10 −13 mol L -1 (M), respectively. The 3D interlayer rGO/SnO 2 /PPy nanohybrid is a favorable material constructed for multiple functionalities having the advantages of conducting material PPy, active site SnO 2 NPs and outstanding electrical substrate graphene nanosheet (obtained from EG) in electrochemical detection of HMIs.