Synergistic Effects of Antimony Oxide Embedded Graphitic Carbon Nitride Nanocomposite as a sensing Interface for Hazardous Bisphenol A: An Electrochemical and Computational Approach

Herein, an electrochemical sensor based on antimony oxide/graphitic carbon nitride nanocomposite (Sb₂O₃/GCN) was applied for bisphenol A (BPA) electroanalysis in a water sample. This composite and its components were characterized with X-ray diffraction (XRD) spectroscopy, UV–visible spectroscopy, Raman spectroscopy, Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). Electrochemical characterization of a pencil graphite electrode (PGE) modified with Sb₂O₃/GCN, Sb₂O₃ nanoparticles (Sb₂O₃ NPs) and graphitic carbon nitride (GCN) show that the Sb₂O₃/GCN modified pencil graphite electrode (PGE/Sb₂O₃/GCN) has the highest electroactive surface area and electronic conductivity. Theoretical calculation of the adsorption energies of BPA/GCN complex and its variants revealed that hydrogen bonding and π- π interaction between GCN and BPA contributed to the electrocatalytic oxidation of BPA at the proposed sensor. The limit of detection of BPA at PGE/Sb₂O₃/GCN was estimated to be 5.61 μM. The calibration curve depicting the changes in peak current with BPA concentration showed two linear ranges at 8–60 μM and 60–140 μM. Also, the proposed sensor offered a percentage recovery of 102.43% for BPA in spiked bottled water. These figures of merit as well as the outstanding selectivity, remarkable repeatability and good reproducibility of the proposed sensor are indications that PGE/Sb₂O₃/GCN is a useful analytical tool for BPA electroanalysis in water samples.

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