M.Phil / MS
Permanent URI for this collectionhttps://repository.cuilahore.edu.pk/handle/123456789/30
This collection archives the complete set of theses produced by students of the COMSATS University Islamabad, Lahore Campus.
Browse
12 results
Search Results
Item Molybdenum Disulfide-Metal Organic Framework as Electrode Material for Heavy Metal Ions Detection in Aqueous Media(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Fatima Amjad; CIIT/SP24-R06-006/LHR; Dr. Sara Riaz; LHR TP 10017Heavy metal ions (HMIs) are highly hazardous environmental pollutants that pose major threats to aquatic ecosystems and human health due to their non-biodegradable nature and strong tendency to accumulate in living organisms. Therefore, it is essential to develop efficient electrode materials for their electrochemical detection in water. For heavy metal ions detection, a hybrid electrode material based on molybdenum disulfide (MoS₂) and an ytterbium-based metal–organic framework (Yb-MOF) was synthesized and characterized. MoS₂@Yb-MOF composite was developed by synthesizing MoS2 nanosheets and combining them with Yb-MOF to synergistically integrate the active edge sites of MoS2 with high surface area and abundant coordination sites of porous framework of the Yb-MOF. A flexible and conductive electrode was fabricated by directly integrating the composite onto a carbon cloth surface. The successful formation of composite material was confirmed through structural and morphological characterization using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Electrochemical studies conducted using cyclic voltammetry and electrochemical impedance spectroscopy confirmed improved charge transfer behavior and enhanced electrochemical activity of the composite electrode relative to the individual components. These results suggested that the MoS₂@Yb-MOF composite is a promising electrode material for electrochemical detection of heavy metal ions in aqueous media.Item N/S co-doped Reduced Graphene Oxide Fabricated Carbon Cloth Electrode for Flexible Supercapacitor(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Nimra Pervaiz; SP22-R06-012; Dr. Sara Riaz; LHR TP 8651Flexible supercapacitor have gained much attention as energy saving devices to power up portable and wearable electronics. The basic principles recognized for traditional capacitor are also applicable to flexible supercapacitors. Nevertheless, flexible supercapacitors have improved charge storage, exceptional flexibility and less resistance, leading to high capacitive performance than traditional capacitors. As compared with batteries, supercapacitors possess very high power density. Therefore, electrode material owing improved power density and energy density with outstanding cycling stability is fabricated. In this research, graphene oxide doping with nitrogen and sulphur was performed. The synthesized material was characterized using Raman spectroscopy, X-rays diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy and X-ray photoelectron microscopy. Electrochemical activity was studied by galvanostatic charge-discharge, electrochemical impedance spectroscopy and cyclic voltammetry employing carbon cloth as substrate for electrode substance. The specific capacitance of N/S-rGO obtained from electrochemical experiment is 290 Fg-1 at current density of 1 Ag-1. The energy density was calculated to be 40 Wkg-1 at power density of 500 Wh kg-1. These outcomes suggest N/S-rGO is potential electrode material to be employed in the high performance supercapaitors.Item Synthesis of Modified MXene for its Application as Flexible Supercapacitor Electrode Material(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Sidra Mehboob; SP23-R06-020; Dr. Sara Riaz; LHR TP 9467Greenhouse gas emissions and the depletion of finite resources are two major environmental issues brought on by the current reliance on fossil fuels to meet energy demands. Making the switch to renewable energy sources like solar and wind is crucial, but their inconsistent availability calls for efficient storage options. Among these, electrochemical energy storage devices supercapacitors in particular stand out as viable choices because of their long-lasting performance and high power efficiency. As a result, the supercapacitor, an energy storage device, has garnered a lot of attention because of its long lifespan, high cycling stability, environmental safety, and quick charge/discharge rate. In comparison to batteries, supercapacitors have a very high power density. Supercapacitor electrode material is made with higher energy and power density and excellent cyclic stability. In present work, ZIF-8, ZIF-67, MXene, Core shell ZIF-8/ZIF-67 and final composite MXene@ZIF-8/ZIF-67 were synthesized. The final composite was synthesized by self-assembly method with non-covalent interactions. The fabricated material was analyzed by FTIR. Different electrochemical characterizations such as CV, GCD and EIS were performed. The active electrode material was coated on carbon cloth by drop casting method. The potential window is from -0.2 to 1.0 V in 3M sulphuric acid. Composite has specific capacitance 83.3 F/g at 0.5 A/g current density with power and energy density at 0.25 Wkg-1 and 43.3 Whkg-1. This is a good material for enhancing the supercapacitor performance.Item Functionalized Graphene Oxide Modified Carbon Cloth Electrode for Supercapacitor Applications(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-26) Mudassar Jamil; FA21-R06-008; Dr. Sara Riaz; LHR TP 8443Supercapacitors have gained significant attention as energy storage devices due to their high-power density, fast charge-discharge rates, and long cycling life. Supercapacitors can provide a substantial amount of power for acceleration and regenerative braking, complementing the energy storage provided by batteries. In this study, we focused on evaluating the potential of graphene oxide (GO) based composite as a supercapacitor material. The objective was to evaluate its electrochemical performance, cyclic stability, and energy storage capabilities. GO was modified first by iron oxide nanoparticles and then hydroxy porphyrin is attached on the surface on GO by non-covalent interaction to make a hybrid composite. The material was characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The results confirmed the successful preparation of GO composite material with desired properties, including a high surface area and unique structural features. Moreover, electrochemical tests were conducted to assess the performance of different prepared material as a supercapacitor electrode material. Galvanostatic charge-discharge measurements revealed the capacitance and charge holding capability of our composite material. From the electrochemical experimental data, the capacitance performance of the GO/Fe3O4/TPPH composite was about 659.5 F/g at a current density of 2 A/g. This capacitance was competent in comparison the capacitance of GO/Fe3O4 and GO which was 401.7 F/g, 155.5 F/g respectively. The energy density calculated for 2 A/g was calculated 74.19 Wh/Kg with the power density of 3215.8 W/kg. In conclusion, the final composite performed very well for supercapacitor application.Item Functionalized Graphene Oxide-MOF Composite for Supercapacitor Application(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-26) Muhammad Hassan Zaheer Khan; FA21-R06-004; Dr. Sara Riaz; LHR TP 8441The world is facing an energy crisis due to continuous increase in the demand of energy with rising population and industrialization. This demand is fulfilled by the burning of fossil fuels that leads to environmental pollution and global warming due to greenhouse gases. The use of green sources of energy like solar, wind and water has been growing but these are not continuous sources of energy. Thus, the energy storage device supercapacitor has attracted much attention because of its high cycling stability, environmental safety, fast charge/discharge rate and long life cycle. The power density of supercapacitors is very high as compared to batteries and Fabrication of supercapacitor electrode material owing high energy and power density with excellent cyclic stability is performed. In present work, graphene oxide is functionalized with a subclass of MOF, ZIF-67 and further modified by attachment of Porphyrin with non-covalent interactions. The fabricated material was analyzed by FTIR, XRD, Raman spectroscopy and SEM. The electrochemical activity and stability was analyzed by CV, GCD and EIS techniques, coating the electrode active material on carbon cloth at potential window -0.3 to 0.3 in 1M H2SO4 solution. The results exhibited that the synthesized material has high excellent energy and power density and excellent cyclic stability.Item Functionalized Graphene Oxide-MOF Modified Pencil Electrode for Heavy Metal Ions Detection(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-26) Sania Sakhawat; FA21-R06-025; Dr. Sara Riaz; LHR TP 8455viii Abstract Functionalized Graphene Oxide-MOF Modified Pencil Electrode for Heavy Metal Ions Detection By Sania Sakhawat In aqueous system, environmental pollution due to heavy metal ions is harmful for aquatic life as well as for human beings. Heavy metal ions cannot be degraded easily. Instead, they enter directly in human bodies or via food chain. Metal ions have the potential to change into more dangerous forms inside the body or have an immediate impact on metabolic processes. Heavy metal ions toxicity results in a number of various disorders. Therefore, there is a necessity for an effective strategy to detect HMIs. Numerous electrodes have been developed in this field for the purpose of detecting and removing toxic contaminants from aqueous systems. However, there is still a need to enhance the performance of sensors. In this particular investigation, a composite material comprising of graphene oxide (GO) and Metal-Organic Framework (MOF) ZIF-67 was synthesized. To detect Harmful Metallic Ions (HMIs), the modified composite material was applied to a pencil graphite electrode. The synthesis of graphene oxide involved a modified version of Hummer's method, while the MOF ZIF-67 was synthesized using a hydrothermal approach. Various characterization techniques such as FTIR, Raman, XRD, and SEM characterizations were performed to check synthesis. Electrochemical characterization was conducted using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) techniques. A potential range of -0.6 to 0.6 mV, with a scan rate of 100 mV/s, was applied in the presence of a 5 mM [Fe (CN) 6]-3/-4 solution. DPV technique was performed to check electrochemical performance of modified electrode material to detect HMIs Calculated LOD for Pb+2 and Hg+2 was 0.01 μM and 0.04 μM respectively.Item 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 7564Heavy 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.Item Fabrication of a Suitable Visible Light Driven Photocatalyst for Sustainable Production of Hydrogen from Water Splitting(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-24) Ayesha Nawaz; FA19-R06-038; Dr. Sara Riaz; LHR TP 7326Excessive use of fossil fuels has caused a lot of environmental damage so they must be replaced with sustainable energy resources. Hydrogen has clean and renewable properties so it can be used as a sustainable energy resource. Photocatalytic water splitting is an efficient way of producing hydrogen but it requires an efficient photocatalyst having high photochemical stability, efficient charge separation capability, good light harvesting properties and suitable band gap. Tungsten oxide has suitable properties for photocatalytic water splitting but it suffers from recombination of photogenerated charge carriers. Herein, different composites of tungsten with transition metal borides and oxides of copper and nickel have been successfully synthesized by precipitation method. FTIR studies, XRD analysis and SEM of the prepared composites, WO3-NiCoB, WO3-CuO-NiO, WO3-NiB and WO3-CuO-NiB have been done for detection of functional group, investigation of crystalline and structural properties, and study of the surface morphology of prepared composites. The photocatalytic activity of WO3, WO3-CuO-NiO and WO3-NiCoB has measured by photodegradation of AO-II. The results of activity showed that WO3-NiCoB worked better in photodegradation of AO-II in comparison to its other counterparts, WO3 and WO3-CuO-NiO.Item A Non-Enzymatic Dopamine Sensor Based on MoS2 Nanosheets Modified Carbon Cloth (CC) Electrode(Library Information Services COMSATS University Islamabad Lahore Campus, 2020-02-20) Mariam Sabar; SP19-R06-002; Dr. Sara Riaz; LHR TP 6506Dopaminergic neurons are the source of production of neurotransmitter called as dopamine (DA). It serves as chemical carrier in hormonal, renal, cardiovascular and central nervous system. The behavior of brain related with motivation and reward is controlled by dopamine in humans. The irregular level of dopamine results in many neural diseases which includes Alzheimer’s disease, less attention hyperactivity disease, Parkinson’s disease, schizophrenia as well as restless legs syndrome. It also gives information about probability of drug addiction. For that reason, an accurate method for the detection of dopamine is necessary. Here we described a material consisting of molybdenum disulfide nanosheets (MoS2 NSs) which were deposited on a Carbon Cloth (CC) electrode that is well adapted for sensitive and selective detection of level of dopamine. The molybdenum nanosheets deposited on CC was made by hydrothermal method. The composite was characterized with various characterization techniques like Scanning electron microscope (SEM), Cyclic Voltammetry, Fourier transform infrared spectroscopy (FTIR), Amperometric i-t method and electrochemical impedance spectroscopy. The composite represents excellent electrochemical properties like more electrochemically active surface, large capacitance current, more conductivity and more porosity as shown by different electrochemical studies. The carbon cloth electrode shows good electrocatalytic ability for dopamine oxidation. The electrode operated best at working potential as low as -0.2 V (vs. Ag/AgCl). It responds linearly to dopamine within 0.25mM to 4mM concentration. The sensor has good selectivity, better stability, repeatability and reproducibility.Item Detection of Heavy Metal Ions using a Composite of Graphene Oxide, Iron Oxide and Metal Organic Framework(Library Information Services COMSATS University Islamabad Lahore Campus, 2020-02-19) Farhan Nazir Ahmad; FA18-R06-005; Dr. Sara Riaz; LHR TP 6489Heavy metals are non-biodegradable, tend to accumulate in living organisms and cause serious health problems. Therefore, effective treatment of heavy metal ions in aqueous media is critical for public health. For selective and sensitive detection of Pb+2, Hg+2 and Cu2+, glassy carbon electrode was modified by a composite of Graphene oxide, metal organic framework and iron oxide. GO serves as backbone of MOF and iron oxide. It improves conductivity by enhancing electron transfer rate in matrix. Moreover, there are interactions between hydrophilic groups of GO and metal cations. GO, MOF and composite of GO-iron oxide was characterized by FTIR and XRD. The detection performance of electrode modified by composite of GO-MOF-iron oxide and GO-iron oxide was explored by EIS and CV. On introduction of MOF-5 to composite of GO-iron oxide, MOF-5 blocks active sites of composite and deactivate it, as MOF-5 hinders transfer of electron. While composite of GO-iron oxide shows excellent heavy metal ions adsorption, high capacitive current and better sensitivity as compared to composite of GO-MOF-iron oxide. This is all attributed to better electron transport properties, good electronic conductivity and large surface area of GO-iron oxide which lead to excellent catalytic response towards heavy metal ions.