An effective sensing platform of graphite-based Zr-CdFe2O4 nanoparticle for electrochemical sensing of heavy metal Pb2+ ions and Sunlight-induced photo-degradation activity

In this current study, the Zr-CdFe₂O₄ nanoparticle (ZCDF NPs) was fabricated by a facile green-mediated (Tulasi extract) combustion method. Their structural properties were well probed through various spectral studies such as Powder-X-ray diffraction (PXRD), Scanning Electron Microscopy- Energy Dispersive X-ray (SEM-EDAX), Fourier Transform Infrared Spectroscopy (FT-IR), and UV–Visible spectroscopy. The XRD results possess a more optimistic with controlled particle size (29 ± 0.5 nm) and crystalline nature of ZCDF NPs. The change in electronic characteristics of CDF NPs by the impact of Zr dopant was recorded by UV–Visible absorption spectroscopy. The lower energy band gap (3.41 eV) of ZCDF NPs associated to trapping electrons-holes and its enhanced dye degradation activity measured using Kubelka–Munk relation. The Ec_B & Ev_B edge potentials of ZCDF NPs were measured to be -3.93 and -1.73 eV, respectively, using observed of electronegativity of ZCDF NPs of 1.67 eV. An excellent photocatalytic performance on Rose Bengal (RB) dye under Sun-light irradiation was observed to be 87.5% at 60 min and its kinetic rate of 34.22 × 10^–3 min⁻¹. The consequence of Zr ions over their electrochemical properties were effectively studied by CV, EIS and GCD electrochemical techniques in 0.1 M KCl using 3-electrode system. The measured specific capacitance of modified carbon-ZCDF electrode was reported to be 186 F/g at current density (1 A/g) using GCD plots. An excellent electrochemical sensing analysis of prepared carbon-ZCDF NPs paste electrode on Lead (Pb²⁺) metal ions at different concentrations of 1–5 μM evidenced by existence of additional peak at—0.93 V potential in CV plot measured between the potential window from + 0.6 to -1.2 V. This experimental measurements finds an effective and promising new route for electrochemical detection of various heavy metal substance in electrolyte.