Emerging applications of sustainable modified CdO/Ag-CdO NPs for electrochemical sensitive and selective detection of mercury (Hg+) heavy metal
B.S. Surendra, H. N. Sowmya, T. Kiran, M Bhaskar, S.K. Rajappa, B. Uma, Syed Khasim, H. C. Ananda Murthy, Kah‐Yoong Chan
Abstract
The sensitivity of developed electrode has gained significant attention for potential energy storage and electrochemical sensor activities. The modified nano-CdO/Ag-CdO-carbon paste electrodes were developed for electrochemical detection of mercury (Hg + ) heavy metal. The synthesized samples were well characterized through PXRD (Powder X-ray diffraction), SEM-EDAX (Scanning Electron Microscopy-Energy Dispersive X-ray Analysis), XPS (X-ray photo-electron spectroscopy), FT-IR (Fourier transform Infra-Red), and UV-Visible spectroscopy. The Ag-CdO modified electrode endowed with higher sensing current and Csp (188 F/g) than pure CdO NPs (94.6 F/g) measured by Linear Sweep (LS), Cyclic Voltammetric (CV) and Electrochemical Impedance Spectral (EIS) techniques. The excellent electrochemical sensing action of developed Ag-CdO electrode was examined on heavy metal Hg + ions at 1–5 mM scan rate in 0.1 M KCl. The linear relationship of sensing measurements with smaller concentration (1–5 mM) was observed with its increased current (+ 1.64 × 10 –4 A/cm 2 at 1 mM) at 30 mV/s. LOD of CdO and Ag-CdO electrodes (Hg + Oxid ) were found at 1.91 mM & 2.41 mM (Hg + Red ) respectively with maximum sensitivity at -0.006 V. LOQ of CdO and Ag-CdO electrodes (Hg + Oxid ) were 5.78 mM & 6.98 mM respectively with maximum sensitivity at -0.006 V. The antibacterial measurements of prepared samples were examined for their susceptibility to inhibit the growth of gram-negative ( Escherichia coli) and gram-positive ( Staphylococcus aureus) bacteria. Thus, the synthesized Ag-CdO electrode provides a new insight for determining the concentrations of critical pollutants and processing the various nanoparticles for sensing of cyanogenic heavy metals.