Synergistic Sb2S3-NiS2 heterostructure: A robust electrocatalyst for electrochemical sensing of Hg (II), As (III) ions and carbendazim fungicide

Abstract

We developed a novel modified electrode based on Sb2S3-NiS2 heterostructure for the electrochemical detection of carbendazim, mercury (Hg2+), and arsenic (As3+). XRD, FESEM, HRTEM, and XPS characterization techniques were employed to confirm the formation of Sb2S3-NiS2 heterostructures. In comparison to other electrodes, the Sb2S3-NiS2 modified electrode has a strong electrocatalytic performance towards carbendazim, Hg2+, and As3+ detection. The Sb2S3-NiS2 nanocomposite's superior electrocatalytic activity is ascribed to its high conductivity, charge capacitance, synergistic effect, substantial number of active sites, and metal trap centres. Electrochemical studies such as cyclic voltammetry, LSV, and DPV depict excellent sensing capacity of Sb2S3-NiS2 for carbendazim, Hg2+, and As3+ with an ultralow detection limit calculated as 0.42 nM, 8.3 nM, and 92 nM, respectively. This is much below the upper limit established by the World Health Organization and the US Environmental Protection Agency. The chronoamperometry response and reusability up to weeks suggest excellent and superior stability. Furthermore, the modified electrode successfully detected carbendazim in real samples of apple and tomato juices and Hg2+ ions in the water of the Dal Lake. As far as we know, this is the first report on the Sb2S3-NiS2 heterostructure's electrocatalytic capability. Hopefully, this study will provide new insight into the future fabrication and development of novel electrocatalyst materials.