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 The Role of Fe-BDC-DMF (MOF) as Substrate in Tuning Electrochemical Properties of Molybdenum oxide/ Fe-BDC-DMF Nanocomposites for Renewable Energy Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2023) Nida Nadeem; CUI/SP22-RPH-020/LHR; Prof. Dr. Muhammad Ashfaq Ahmad; LHR TP 8783In recent years, transition metal oxide (TMO) and metal organic frameworks (MOFs) have become effective options for use as electrode materials in energy storage systems. Due to its intercalation potential and effective interaction with Li ion, molybdenum oxide, a TMO material, offers interesting uses for Li-ion batteries. Unfortunately, pure Mo-oxide performs poorly in electromedicine. By creating novel composites, their electrochemical performance is improved, and MOFs are one of the most qualified options since they serve as support substrates for functional materials like metal oxides. By creating novel composites, their electrochemical performance is improved, and MOFs are one of the most qualified options since they serve as support substrates for functional materials like metal oxides. Although the shape, porosity, and specific surface areas of these kinds of composites are largely determined by the precursors chosen and the experimental setup. In this work, we have synthesized unique Molybdenum oxide/ Fe-BDC-DMF nanocomposites, and their morphology, structural spectroscopy, and electrochemical analysis are studied for optoelectronic and energy storage/conversion applications. The Raman spectra of all the samples shows the characteristic vibrational modes of α-MoO3 , β-MoO3 and MOF. We also calculate crystallite size of all composites through XRD graphs by using scherrer formula and get crystallite size of 14.57,16.93,17.48 nm and observe broader XRD peaks having high FWHM and low crystallite sizes due to disorder arrangements of crystal. We also calculate the specific capacitance, energy density and power density through CV curves through their particular formulas and we observe specific capacitance at various scan rates and composites having high scan rate show less capacitance because the porous nature of MOF is destroyed due to high scan rate. We notice the composite having greater amount of MoO3 has more specific capacitance so we can say that this composite is best for capacitor application as we get higher capacitance of 5000Fg-1 which is greater than all the capacitance that is published so far for MOF and MoO3.Item Synthesis of CeO2/NiFe2O4 Nanocomposites and their Photocatalytic Activity of Methyl Orange Dye under UV-Visible Irradiations(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) ALI BASHEER; CIIT/ FA20-RPH-048/LHR; Dr. Muhammad Hammad Aziz; LHR TP 8003Using the hydrothermal technique CeO2/NiFe2O4 for exceptional photocatalytic activity, nanoparticles are fabricated. Methyl Orange dye according to its toxicity, color, and environmental hazards was used as aqueous pollutant source for photocatalytic experiment results. The synthesized nanoparticles were characterized by various techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM). The photocatalytic activity of synthesized nanoparticles was studied by conducting the degradation of methyl orange under the visible light. PL spectra were verified for the recombination and separation time for the synthesized nanoparticles in different light regions. 88.57% of Methyl Orange was degraded in 120 min. The result attests to low cost, reusable and high efficiency photo catalyst for environmental remediation. The synthesize sample is easily separable using any external magnetic source. In addition, sample results show the shifting of absorption spectrum towards the visible region of light. FTIR and XRD results show the functional and cubic spinel shape photo catalysis formation. SEM images show the morphology of the sample. Reusability and stability experiment exhibit the miner reduction in catalyst efficiency percentage after five cycles. According to extraordinary applications the synthesize sample are used on large scale for Industrial Waste Water treatment process in future.Item Synthesis and Characterization of NiFe2O4/CS Nanocomposites and its application towards Choline Biosensing(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Iqra Khalid; CIIT/SP20-RPH-031/LHR; Dr. Akbar Ali; LHR TP 7715A non-enzymatic choline biosensor was demonstrated with chitosan (CS) supported NiFe2O4 modified on carbon paste electrode (CPE). The NiFe2O4 was synthesized via hydrothermal method to study the choline chloride (ChCl) behaviour towards the distinctive performance of choline. The prepared sample presented cost-effective choline sensing as emerged with CS formed NiFe2O4/CS and immersed with CPE. The synthesized NiFe2O4 was examined with different characterization technique to confirm the formation of specified material. X-ray diffraction (XRD), Fourier- Transmission Infrared spectroscopy (FTIR) and Raman Spectroscopy used to optimize and evaluate the various properties of prepared material. XRD confirmed the cubic inverse spinel crystal structure of NiFe2O4 with crystallite size of 14nm, while FTIR spectra revealed the stretching and bending vibration over the IR frequency range and modes confirmed through Raman spectra frequency range. The modified electrode of NiFe2O4/CS/CPE was used to perform electrochemical studies by voltammogram and evaluated through Cyclic voltammetry (CV). The CV curves taken at different working range (5-15μL) of potential 0.0-+1.0 V and quantified the analyte signal of LoD (0.002μM) considering the S/N=3 across the current system with the linear regression (R2) of 0.99. The prepared electrode showed the low (LoD) at the smaller range of the choline chloride and demonstrated good responseItem Synthesis and Characterization of Doped Metal Oxide/Graphene Oxide Nanocomposites for Electrochemical Sensing of Neurotransmitters(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Muhammad Inam khan; CIIT/FA18-RPH-030/LHR; Dr. Muhammad Aamir Razaq; LHR TP 6089Dopamine is one of the main neurotransmitter of our body. The alteration in the normal concentration give rise to the multiple disorder and diseases. The electrochemical measurements of dopamine with bare electrode is not possible due to various problem like electrochemical fouling, interference species have same oxidation potential and lower concentration of dopamine in biological samples. The modification of working electrode is essential for fast, accurate, selective and sensitive detection of dopamine. Metal oxide/graphene oxide nanocomposites have attracted great attention due to the synergistic effect. Zinc and cobalt nanoparticles contain several properties such as catalytic activity, high surface area, electrochemical activity, and oxygen transferability which are attractive for sensor applications. In this project the main objective is to study the synthesis, characterization and application of a new hybrid material designated as doped metal oxide/graphene oxide. In this work doped metal oxide/graphene oxide nanocomposites has been synthesized by hydrothermal and co-precipitation route. Modification of the glassy carbon electrode (GCE) surface has been by the synthesized nanocomposite. For the detection of neurotransmitters (dopamine) these modified GCE/ZnO/Co3O4 electrodes has been used. The electrochemical properties of the ZnO/Co3O4 modified electrode were investigated by the cyclic voltammetry and amperometric current-time method. The modified electrode has shown high electrochemical activity for the catalytic reduction and detection of dopamine. The nonenzymatic dopamine sensor shows wide linear range of 2- 90 mM (R = 0.97). The hybrid nanocomposite has exhibit the low limit of detection (LOD) 0.26 µmol L-1 , limit of quantification (LOQ) 0.813 µmol L-1 and sensitivity 1.32 µA. µmol L-1 were found.Item Development and Electrochemical Characterization of Nanocomposites for Biogas Based Fuel Cells(2018) Asia Rafique; CIIT/FA13-PPHY-003/LHR; Dr. Rizwan Raza; LHR TP LHR TP 5602There is an urgent need to explore affordable and renewable energy resources because of the decline in reserves of fossil fuels. Biomass is an abundantly available resource in nature and can be used to generate energy in a sustainable manner. Fuel cells deliver a combination of advantages and make use of renewable energy sources. Solid oxide fuel cells (SOFCs), specifically, overcome the petroleum scarcity issue by using biofuel. The aim of this thesis is the development of nanocomposite electrolytes and anode composite catalysts for low-temperature SOFCs fuelled with biogas for clean energy applications. In the present work, Sr/Sm-doped ceria (Sr-SDC) nanocomposite electrolytes with a core shell structure are synthesized with different compositions for low temperature SOFCs. A co-doping technique is successfully used to achieve a significant enhancement in the ionic conductivity of 0.50 S/cm at 600 ˚C for the nanocomposite electrolyte Sr0.1Sm0.1Ce0.8O2-δ-carbonate. The carbonate phase (shell layer) acts as a barrier and protects the SDC (core) from the partial reduction by the fuel. This carbonate shell introduces an interface between these two phases, which is the key to realizing the interfacial super-ionic conduction pathways. This work also describes the development of ceria electrolytes that are doped and co-doped with lanthanum (La) and zirconium (Zr) and show excellent thermal stability. The ionic conductivity of La0.2Ce0.8O2-δ (LDC), Zr0.2Ce0.8O2-δ (ZDC) and Zr0.2La0.2Ce0.6O2-δ (ZLDC) has been measured in the temperature ranges of 450 °C to 650 °C and LDC achieved a high ionic conductivity of 0.81 × 10-2 S/cm. Thermal expansion coefficients (TECs) of these electrolytes have also been found to have good concurrence and compatibility with commonly used electrolytes and electrodes. The main objective of this work is the development of stable and active anode catalysts that run over biogas as well as hydrogen for low temperature SOFCs. The anode composite Ni0.6Zn0.4- Gd0.2Ce0.8O2-δ (NiZn-GDC) has been developed that exhibits semiconductor conductive behaviour, and a maximum conductivity of 1.37 S/cm has been achieved at 600 ˚C. This composite anode is found to have excellent thermally stability as well as being carbon resistant to coking during testing with biogas. A maximum power density of xii 820 and 548 mW/cm2 has been reported with hydrogen and biogas fuels, respectively, at 600 ˚C. This thesis also describes Ni-based and Ni-free anode catalysts NiLiCu-oxide with LDC for SOFCs fuelled with biogas. The anode composite NLC622-LDC has reported a maximum DC conductivity of 3.47 S/cm with Pmax of 650 and 390 mW/cm2 for hydrogen and biogas, respectively, at 600 ˚C. A Ni free anode catalyst Zn0.2Li0.2Cu0.6O2-δ (ZnLiCu-oxide) is also developed as a potential candidate for biogas-based SOFCs that bypasses the difficulty of carbon deposition and has a maximum conductivity of 4.0 S/cm at 600 ˚C. An open circuit voltage (OCV) of 0.96 V is achieved with maximum power density of 600 mW/cm2 with biogas (50% methane) at 650 ˚C. In the present work, a theoretical model of FC system has been designed using MATLAB software, and it makes use of biomass (animal waste, redwood, rice husk and sugar cane). In the last part of the thesis, a partial research work has been conducted to cast the tapes of NiO-GDC (NiO-Gd0.1Ce0.9O1.95) as anode and GDC (Gd0.1Ce0.9O1.95) as electrolyte via aqueous tape casting method. The aqueous tape casting is an emerging and cost-effective technique for the commercialization of SOFCs but faces challenges with ceria tapes due to its poor mechanical strength and co-sintering of half-cells.Item Exploring the Effects of Graphene Oxide Additives on Ag/NiFe2O4 Nanocomposites for Energy Storage Devices(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025-07-25) Fatima Muhammad; CIIT/FA23-RPH-015/LHR; Dr. Mukhtar Ahmed; LHR TP 9846This study examines the production and characterization of Ag/NiFe₂O₄ nanocomposites enhanced with Graphene Oxide (GO) to improve their energy storage ability. X-ray diffraction (XRD) indicates the creation of a spinel NiFe₂O₄ structure with notable crystallographic planes (311), (220), and (440). The sharpness and intensity of the peaks imply strong crystallinity, whereas other characteristics corroborate the presence of Ag and GO. Raman spectroscopy confirms these findings by displaying specific vibrational modes. The spectra show expanded D and G bands in the GO-doped samples, indicating excellent integration of Graphene Oxide and improved structural disorder, which leads to greater electron mobility. Pure NiFe₂O₄, Ag-doped, and GO-incorporated samples show substantial differences, emphasizing GO's synergistic role in improving structural and electrical characterization. UV-Visible spectroscopy reveals a considerable decrease in band gap energy from 1.43 eV (pure NiFe₂O₄) to 0.237 eV (Ag/NiFe₂O₄), with a little rise to 0.264 eV with GO addition. The tunability of the band gap suggests increased conductivity and photo response, both of which are the desired characteristics for electrode materials in supercapacitors and other energy Storage Devices. Adding GO to Ag/NiFe₂O₄ nanocomposites increases crystallinity, structural flaws, and optical and electrical characteristics. These enhancements establish the composite as a promising contender for next-generation energy storage systems.