M.Phil / MS
Permanent URI for this collectionhttps://repository.cuilahore.edu.pk/handle/123456789/60
This collection archives the complete set of theses produced by students of the COMSATS University Islamabad, Lahore Campus.
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Item Synthesis and Characterization of Hybrid Nanomaterials for Energy and Environmental Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Saba Khaliq; CIIT/FA22-RPH-023/LHR; Dr. Muhammad Ashfaq; LHR TP 9423It is a challenging task to work with composite of hybrid nanomaterials without losing their unique properties. It is a difficult task to get the composites to work together. Researchers aim to find the best ways to mix them while keeping their individual properties intact. Physical parameters like size and shape play efficient role in the synthesis of hybrid nanomaterials. Controlling the composition and structure to tailor properties for specific applications while maintaining cost-effectiveness and sustainability is also a significant concern in this field. Imagine creating tiny superhero materials at the tiniest scale possible. These superhero materials named hybrid nanomaterials made by mixing different ultra-small particles like metal nitrates, graphene oxide (GO), and reduced graphene oxide (R-GO) and synthesized by a modified hummer’s method. Characterizations like XRD, CV, and UV-visible and RMAN spectroscopy of synthesized hybrid nanomaterials was carried out to analyze their application in the fields of energy and environment. Hybrid nanomaterials based on graphene oxide and metal nanoparticles efficiently purify water by removing contaminants. These tailored materials, with their modified properties like high surface area and selective sensing capabilities, play an important role in tackling challenges related to pollution control, environmental monitoring, storage, and clean energy generation. Ongoing research aims to optimize these hybrid nanomaterials for different sustainable energy and environmental applications.Item Study of Quantum Effects and Porosity of the Perovskite Materials for Energy and Photocatalysis Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Asifa Kusar; CIIT/FA20-RPH-007/LHR; Dr. Muhammad Ashfaq Ahmad; LHR TP 7972Energy conversion devices are widely being used to convert chemical into electrical. Fuel cell is the most prominent candidate among all the energy conversion devices. The operating temperature of conventional fuel cell is very high because of high electrolyte resistance. Develop better energy storage and conversion devices is the main goal of the scientists and engineers because of increasing global temperature due to consumption of fossil fuels. Fuel cell has potential and capability to give maximum energy without deteriorating environment. Electrode is the most important component of fuel cell because reaction takes place on it. Lanthanum and ferrite-based perovskite material are investigated quantum mechanically to find out the impact factor on working of SOFCs. Among the prepared samples the material with high concentration shows batter crystal structure, photocatalytic activity and improved conductivity. Samples have been investigated by various techniques showing considerable porosity, stability and Prescence of reactive metal cations like La+2, Sr+1, Cu+1 , Fe+2 and Fe+3 reveal the improved functionality of perovskites as they assist in conductivity, oxidation, reduction and catalytic process. Crystalline structure of the material is determined by XRD, energy band gap can be found by UV-Vis, vibrational characteristics and phase shift of the synthesized material can be found by Raman spectroscopy, materials used in synthesis can be confirmed by FTIR. Among various types of perovskites, the LSF perovskites are best performing material for photocatalytic applications while study of quantum effects reveals that LSCF second to them LCF are best optimized material for energy applications.Item Electronic Structure and Energy Application of Layered Carbide Materials(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Maria Sarfraz; CIIT/FA20-RPH-015/LHR; Dr. Rizwan Raza; LHR TP 7978This project prepares the silicon carbide and MgZnO-based semiconductor materials for photocatalysis applications. An efficient photocatalytic material is required for proper working to enhance the efficiency of clean energy devices. The efficiency of photocatalysis water-splitting reaction has been limited. However, carbide and zinc oxide-based catalysts are developed to address such issues and discuss the reaction mechanism. Therefore, in this research work, SiC composite is made by hydrothermal method while MgZnO semiconductor materials are made by sol-gel method. To analyze the synthesized samples' structural properties, XRD has been carried out and find out SiC composite and MgZnO materials. RAMAN and UV spectroscopy is used to detect vibrational, rotational, and other states in a molecular system, and materials' optical properties have been studied, respectively. Further, electrochemical characterizations include EIS, Linear sweep voltammetry, and cyclic voltammetry. It has been observed that both materials are actively involved in electrochemical reactions. It can be concluded that the best performance among the two prepared samples is given by the model MgZnO. The reason is that MgZnO behaves like a promising photocatalyst compared to that SiC. Theoretical studies have been performed using Density Functional theory calculations to study the optical parameters, electronic structure, the density of states, and band gapItem Development of GO-MnO2 Nanocomposite based Electrode for Energy Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Mariyam Ashraf; CIIT/SP20-RPH-036/LHR; Dr. Muhammad Ashfaq Ahmad; LHR TP 7717Transition metal oxides exhibit unique properties as catalytic activity, piezoelectricity, and superconductivity and are widely used in energy storage and conversion devices. For energy storage and transfer devices like supercapacitors and batteries have been widely researched on the purpose of obtaining desirable performances. In this work, Manganese based oxide materials synthesized by Modified Hummers method, hydrothermal method and sol-gel technique respectively and their functionalities are investigated as electrode function of supercapacitor devices. The perposed materials are GO, MnO2, GO-MnO2, Li (0.1) doped MnO2 and Li (0.2) doped MnO2. Their investigations consist of various characterizations such as XRD, Raman and FTIR. The XRD pattern of MnO2 (JCPDS: 44-0141) having tetragonal structure. The average crystallite size of MnO2 is 24.34 nm. In XRD pattern of Li (0.1) doped MnO2, the cubic structure of the Mn-O confirmed with JCPDS card: 96-201-9466, average crystallite size (D) is 28.93 nm and the cubic structure of the Li-O confirmed with JCPDS card: 96-151-4099, average crystallite size (D) is 31.09 nm. The orthorhombic structure of the LiMn-O confirmed with JCPDS card: 01-081-1706 and average crystallite size (D) is 22.16 nm. FTIR technique is employed to study the chemical composition and its bonding. All the samples accommodate numerous functional groups like epoxy, carbonyl, hydroxyl, and carboxyl. Raman spectroscopy is used to detect vibrational, rotational, and other states in a molecular system, capable of probing the chemical composition of materials. Electrochemical performance of prepared electrodes was evaluated by cyclic voltammetry (CV), galvanic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements. The specific capacitance, energy density and power density for GO-MnO2 electrode are 861 Fg-1 at 1Ag-1, 0.0298Whkg-1 1Ag-1, and 0.00948Whkg-1 1Ag-1 from GCD curve. From Nyquist plot the MnO2 shows good electrical conductivity as compared to GO-MnO2 and when replace Li with GO the conductivity increased by increasing the ratio of doping material. It is concluded that the electrode material shows good specific capacitance with small value of energy and power density. A computational approach is also used to analyze the thermometric properties such as Seebeck coefficient (S (T)), electrical conductivity (σ (T)), thermal conductivity (k(T)), power factor (P (T)), and figure of merits (Z (T)) by software Quantum espresso using Plane-wave approximation which shows that MnO2 having excellent thermoelectric properties.