3D interlayer nanohybrids composed of reduced graphenescheme oxide/SnO_2/PPy grown from expanded graphite for the detection of ultra-trace Cd~(2+) , Cu~(2+) , Hg~(2+) and Pb~(2+) ions

摘要

The three dimensional (3D) interlayer rGO/SnO2/PPy nanohybrids, based on reduced graphene oxide (rGO) obtained from expanded graphene (EG), SnO2nanoparticles (NPs) and polypyrrole (PPy) were obtained by facile method. The rGO/SnO2/PPy nanohybrid electrodes were composed of a thin conducting film of PPy on the surface of rGO/SnO2(EG: Sn molar ratio of 1.2:1), used for the determination of ultra-trace ions (Cd2+, Cu2+, Hg2+and Pb2+) with the square wave anodic stripping voltammetry (SWASV) technique. Among the rGO/SnO2/PPy, rGO/SnO2(rGS), rGO/PPy (rGP) and pure polypyrrole (PPy) samples, the sensitivity and current density of rGO/SnO2/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/SnO2/PPy-4 nanohybrids modified electrode toward Cd2+, Cu2+, Hg2+and Pb2+ions was 7.5 × 10−13, 8.3 × 10−13, 8.1 × 10−13and 8.8 × 10−13mol L-1(M), respectively. The 3D interlayer rGO/SnO2/PPy nanohybrid is a favorable material constructed for multiple functionalities having the advantages of conducting material PPy, active site SnO2NPs and outstanding electrical substrate graphene nanosheet (obtained from EG) in electrochemical detection of HMIs.