Browsing by Author "LHR TP 7564"

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    Electrochemical Detection of Heavy Metal Ions Using Graphene/MOF Modified Electrode
    (Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Mariam Ghafoor; SP20-R06-009; Dr. Sara Riaz; LHR TP 7564
    Heavy metals pollution is due to agriculture, mining industry, and industrial activities. Once heavy metal ions pollute environment specially water bodies, they are very difficult to degrade by nature for decades. Over time they accumulate in body and pose serious health problems. Because of these effects, it is necessary to detect heavy metal ions. Therefore, It is essential to design such electrode materials with high porosity and large surface area for their wide range of applicability. Metal Organic Framework have been regarded as the promising electrode materials constituting porous carbon-based electrode materials for electrochemical detection of heavy metal ions. In present work, we fabricated cobalt derived Metal Organic Framework comprising of Zeolitic Imidazolate framework (ZIF-67) and then using ZIF-67 as a precursor for the synthesis of graphene oxide (GO) coated ZIF-67 composite through a facile solvothermal synthesis method. Structural analysis of prepared material was done by using FTIR, Raman analysis and XRD. Electrochemical characterization of our prepared composite electrode material was performed through Electrochemical impedance spectroscopy (EIS) and Cyclic Voltammetry (CV) techniques at potential window of -0.2-0.6 mV/s in 5mM [Fe (CN)6]-3/-4 containing 0.1 M KCl using glassy carbon electrode as a current collector. Differential pulse Voltammetry used for individual detection of toxic heavy metal ions such as Pb, Cr, Hg, and As with lower limit of detection i.e 0.01(μM), 0.12(μM), 0.009(μM), and 0.31(μM) respectively below the permissible limit by WHO. Results revealed that synthesized composite (GO/ZIF-67) electrode material has better electrochemical performance as compared to ZIF-67/GCE, GO/GCE, and bare GCE electrode. Therefore, GO/ZIF-67 composite is determined to have good capability as electrode material in heavy metals detection application due to its porous tunable structural composition.
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    Synthesis and Characterization of PANI@cellulose Nanocomposite based Electrochemical Sensor for Environmental Remediation
    (Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Nageen Shoukat; SP20-R06-010; Dr. Lubna Sherin; LHR TP 7564
    In this work, porous CuO-NiO/CA/PANI@Ni-foam sensor electrode has been designed using electospinning of CA/PANI composite on Ni-foam and then drop casting of CuO-NiO nanoparticles for detection of bisphenol A (BPA). 3D nickel foam has been chosen as electrode substrate for the direct growth of CA/PANI since Ni-foam has the advantages of excellent electrical conductivity, low cost, commercial availability, and porous structure, which provides large surface area for synthesis of nanofibers. This direct grown structure of CuO-NiO/CA/PANI@Ni-foam provides exceptional properties, such as reduced resistance, good electron transport, better adhesion stability and the excellent electrical conductivity as compared with non-direct synthesized electrode. Furthermore, a synergetic effect between CuO-NiO/CA/PANI and Ni-foam substrate enables the electrode for excellent sensing behavior towards BPA. The resultant CuO-NiO/CA/PANI@Ni-foam was analyzed using Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Different electrochemical methods such as cyclic voltammetry, electrochemical impedance and differential pulse voltammetry were used for evaluation of synthesized sensor’s performance against BPA. Under optimal conditions, a linear response was observed against BPA and very low limit of detection as well (LOD=0.6uM). The CuO-NiO/CA/PANI@Ni-foam electrode demonstrated high reproducibility, consistency, and stability when used to detect BPA in water. The synthesized sensor's results demonstrated that it was extremely selective for the detection of BPA, suggesting that it could be useful in environmental based surveillances.