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

We developed a novel modified electrode based on Sb 2 S 3 -NiS 2 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 Sb 2 S 3 -NiS 2 heterostructures. In comparison to other electrodes, the Sb 2 S 3 -NiS 2 modified electrode has a strong electrocatalytic performance towards carbendazim, Hg²⁺, and As³⁺ detection. The Sb 2 S 3 -NiS 2 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 Sb 2 S 3 -NiS 2 for carbendazim, Hg^2+, 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 Sb 2 S 3 -NiS 2 heterostructure's electrocatalytic capability. Hopefully, this study will provide new insight into the future fabrication and development of novel electrocatalyst materials. [Display omitted] • An electrocatalyst, Sb 2 S 3 -NiS 2 , was prepared using a facile hydrothermal method. • XRD, FESEM, XPS and HRTEM analyses confirm the formation of the electrocatalyst. • Sb2S3-NiS2 showed excellent electrochemical detection of carbendazim fungicide. • The catalyst offered very good stability with low LOD and high selectivity. • The electrocatalyst displays promising recovery in real environmental samples. [ABSTRACT FROM AUTHOR]