Highly sensitive electrochemical detection of Pb(II) based on excellent adsorption and surface Ni(II)/Ni(III) cycle of porous flower-like NiO/rGO nanocomposite

Abstract Herein, combining the good catalysis of NiO with high adsorption and conductivity of reduced graphene oxide (rGO), the electrochemical sensing interface was constructed using the porous flower-like NiO/rGO nanocomposite modified glassy carbon electrode (GCE). The result of Pb(II) detection was obtained with high sensitivity of 92.81 μM μA−1 and low detection limit of 0.01 μM by square wave anodic stripping voltammetry (SWASV). The reasonable sensitive mechanism for enhancing electrochemical performance is that the excellent adsorption capacity and Ni(II)/Ni(III) cycle on surface of NiO/rGO nanocomposite could improve the electrochemical detection signal. Furthermore, the proposed method achieved the high anti-interference on the determination of Pb(II) in the co-existence of Cd(II), Cu(II), Hg(II). The excellent stability and reproducibility were also confirmed by repeatedly test. In addition, the concentration of Pb(II) in real water samples from Taochong wastewater treatment plant in Hefei city were analyzed and calculated accurately. These results indicates that the NiO/rGO nanocomposite as a promising electrode modifier could be potentially applied in electrochemical sensor for detecting Pb(II).