One-pot synthesis of CdxZn1-xS-reduced graphene oxide nanocomposites with improved photoelectrochemical performance for selective determination of Cu2+

A series of CdxZn1-xS-reduced graphene oxide (CdxZn1-xS-rGO) nanocomposites were successfully prepared by a facile one-pot reaction. In this reaction system, H2S gas acted as a sulfide source as well as a reducing agent, resulting in the formation of CdxZn1-xS nanoparticles and simultaneous reduction of graphene oxide sheets to rGO. The photoelectrochemical (PEC) performances of CdxZn1-xS-rGO nanocomposites were further investigated under visible irradiation, which showed that the photocurrent intensities were influenced by the cationic composition (x) in CdxZn1-xS-rGO nanocomposites. Compared with other CdxZn1-xS-rGO nanocomposites, the Cd0.5Zn0.5S-rGO nanocomposite displayed optimal photocurrent intensity, which was 5 times greater than that of CdS NPs. Based on Cu2+ selective suppression of the photocurrent intensity of the Cd0.5Zn0.5S-rGO nanocomposite, the photocurrent suppression obtained was linearly proportional to the logarithm of the concentration of Cu2+. The resulting Cu2+ photoelectrochemical sensor showed good performance including a wide linear range of 0.02 mu M to 20 mu M, low detection limit of 6.7 x 10(-9) M (S/N = 3) and good anti-interference ability.