Department of Chemistry
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Item 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 7564In 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.Item Synthesis and Characterization of Polysaccharide-MOF Composites for Environmental Remediation(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Osama Kokab; SP20-R06-002; Dr. M. Shahid Nazir; LHR TP 7557MOFs are porous co-ordination networks/polymers which are highly crystalline substances with enhanced porosity, large surface area and improved overall attributes. These cages comprise of metal ion clusters which serve as the secondary building units (SBUs). Based on the coordination geometry of the organic linkers with metal ions; their structure and unique attributes can vary accordingly. Zeolitic Imidazole Framework-8 (ZIF-8) have improved structural porosity, flexibility, surface functionality and crystalline nature making it feasible to be utilized in various applications including the gas storage, CO2 adsorption, alkane/alkene separation and the catalysis. The biodegradability, higher surface area, and flexible binding interaction between the cellulose and ZIF-8 have made it an ideal choice for the various water remediation applications. The poor wet chemistry of the ZIF8-Cellulose composite is reported previously as the cellulose swells and loose dimensional stability in aqueous media. To overcome this problem, the ZIF8-APTES-Cellulose composite is synthesized which have high hydrophobicity and aqueous stability. The wet chemistry is tested by measuring the water contact angle which is 139.5°. The FTIR analysis shows a significant peak at 450cm-1 confirming the Zn-N bond along with peaks at 1550cm-1, 1480 cm-1, 1080cm-1, and 1020 cm-1 confirming the N-H bending of APTES, C=N vibration, C-N vibration of imidazole and C-O vibration of the composite respectively. Moreover, XRD analysis of the composite shows characteristic peak positions at 7.3°, 10.3°, 12.7°, 18°, 22.7° and 35.02° confirming the presence of ZIF8, APTES and cellulose. The dye degradation efficiency for the composite is explored at different conditions such as pH, dose of adsorbent, and concentration of dyes to achieve the optimized results. The maximum efficiency for the degradation of Congo Red dye is achieved 95% with 4mg dose of adsorbent at pH 4.0. This study opens up avenue for the dye remediation of wastewater.Item Designing and Fabrication of MOF Based Electrochemical Sensor for Potential Application in Environmental Remediation2025(2025) Arfa Tahir CIIT/FA23-R06-006/LHR; Dr. Lubna Sherin; lHR TP 9684Contamination of fresh water bodies by heavy metal ions (HMIs) has been a concern across the world. Due to its bioaccumulation and non-degradability, lead (Pb) and mercury (Hg) are some of the HMIs which are toxic and chronic to human health. Identification of these water bodies prior to utilization is important. In detection of HMIs, electrochemical sensing may be proved to be a sensitive detection platform. In this case, an energy-efficient microwave method was applied to synthesize MOF of copper as the central metal ion and L-aspartic acid and Benzene tricarboxylic acid as the linkers. Aspartic acid is a biocompatible amino acid that is found naturally. In the synthesis of MOFs, microwave manufacturing provides a technique that is environmentally less polluting, stable in heat rate, low in reaction time, and high in yield. Good surface properties are exhibited by the MOF as synthesized. Ionic Liquid (EMIM TFSI) addition to MOF has enhanced its conductivity, HMI adsorption sites, and possible sensing platform window. Therefore, for electrochemical sensitive detection of HMIs, the synthesized MOF (L-asp-BTC-cu)/IL composite exhibited large active surface area, excellent charge transfer rate, enhanced conductivity, and time stability. FTIR and XRD were applied to study the synthesized composite. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to identify the electrochemical response of MOF (L-asp-BTC-cu)/IL/GCE. Mercury (Hg) and lead (Pb) were quantified by square wave voltammetry (SWV). Results indicated that the lower limits of detection (LOD) and linear detection range for each of these three HMIs separately and in combination. Obtained limit of detection (LOD) for Pb (II) and Hg (II) were 0.17μM, and 0.36μM respectively.