Hydrothermal synthesis of DyNbO4 hallow spheres anchored on heteroatoms-doped reduced graphene oxide for electrochemical detection of environmental pollutant 4-nitrotoluene

Environmental contamination of nitro aromatic compounds (NACs) from industries causes negative impacts on soil, water bodies, humans, and animals. Therefore, the rapid and accurate monitoring of these residues in ambient water is critical to ensuring a sustainable ecosystem. In this study, a novel dysprosium niobate spheres decorated on heteroatoms-doped reduced graphene oxide (DyNbO 4 @NS-rGO or DNO@NS-rGO) nanostructure-based electrochemical (EC) detection of 4-nitrotoluene (4-NT) has been developed. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller method (BET) measurements were used to investigate the crystalline structure, morphology, and surface properties of the DNO@NS-rGO nanostructure . The EC properties of the modified electrodes were investigated employing cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The DNO@NS-rGO/GCE electrode had a promising sensitivity (1.48 μA μM −1 cm −2 ), low detection limit (LOD: 2.7 nM), and a linear range (BLR: 0.4–78 and 91–941 μM) with desirable selectivity. The sensors also demonstrated superior levels of reproducibility, repeatability, and stability. The system has also been successfully applied for the detection of 4-NT in real water samples with satisfactory recovery. The DNO@NS-rGO nanocomposite represents a robust, eco-friendly, and highly effective system with prospective practical application for nitro-based sensors as trace level detection in environmental samples. Hydrothermal synthesis of novel nanocomposite DNO@NS-rGO and its electrochemical sensing towards 4-nitrotoluene in water samples • Template-assisted hydrothermal method is utilized for the synthesis of DyNbO 4 (DNO). • A novel nanocomposite DyNbO 4 @ NS-rGO was applied for the EC detection of 4NT. • It exhibits a wide linearity, a low LOD, and a high sensitivity for 4NT. • DNO@NS-rGO/GCE exhibits admirable recoveries in ground and river water samples.