An electrocatalytic sensing of 2, 6-dichlorophenol based on Dy₂O₃-Co₃O₄@CeO₂ nanocomposite modified GCE: An enhanced environmental safety

Anthropogenic activities are continuously polluted our environment by releasing various kind of toxic chemicals as waste product. Their removal has gained the impressive importance among the scientists in order to maintain the integrity of our ecosystem. In this present work, Dy₂O₃-Co₃O₄@CeO₂ nanocomposite (NC) was prepared by simple solution method with the aspiration to detect as well as electro-hydrolyzed the toxic chemicals in an aqueous system. Structural, morphological and optical properties of our newly synthesised nanocomposite were investigated by using advanced analytical tools such as ultraviolet–visible difused reflectance spectroscopy (UV-DRS), fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), field emission scanning electron microscope equipped with energy dispersive spectroscopy (FESEM-EDS), and transmission electron microscope (TEM) in addition to Brunauer-Emmet-Teller (BET) analysis. After detailed characterization of newly synthesized Dy₂O₃-Co₃O₄@Ce₂O₃ nanocomposite, it was used with 5 % PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), a conducting polymer binder, to modify the glassy carbon electrode (GCE) as selective electrochemical sensor (Dy₂O₃-Co₃O₄@CeO₂-NC/PEDOT:PSS/GCE). After that, this newly designed Dy₂O₃-Co₃O₄@CeO₂-NC/PEDOT:PSS/GCE was evaluated so as to check its detection as well as electrocatalytic behaviour against the toxic chemicals in an aqueous system using novel electrochemical current–potential (I–V) approach, for the first time. A comparative investigation revealed that this newly designed Dy₂O₃-Co₃O₄@CeO₂-NC/PEDOT:PSS/GCE was very selective against the 2, 6-dichlorophenol (2, 6-DCP) and had good affinity with it even in the company of other interference chemicals. In order to optimise newly developed Dy₂O₃-Co₃O₄@CeO₂-NC/PEDOT:PSS/GCE as an effective as well as selective 2, 6-DCP electrochemical sensor, analytical parameters such as, limit of detection (LOD), limit of quantification (LOQ), sensitivity etc were calculated from slop of calibration curve. The LOD at signal-to-noise ratio (S/N) of 3, LOQ, and sensitivity were calculated as 0.014 ± 0.001 nM, 0.046 ± 0.001 nM, and 65.82 µAµM^-1cm⁻², respectively, over a linear dynamic range (LDR) of our target analyte concentration (0.1 nM – 0.1 M) with r² square value as 0.9988. Consequently, this study enlightens us that this newly fabricated electrochemical sensor, selective only for 2, 6-DCP, is very cost-effective, efficient, and stable over time. Moreover, it also initiates a new way to effectively interrogate the various toxic chemicals in real samples by using a novel electrochemical (I–V) approach based on reported / non-reported different kind of semiconductor nanocomposite modified GCEs as selective electrochemical sensors.