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 Investigation of Ionic Behavior of Boron Doped Ceria Oxide Ion Conductors using Electrochemical Techniques(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Muhammad Nadeem; CIIT/SP20-RPH-022/LHR; Dr. Ghazanfar Abbas; LHR TP 7965In this study, Boron Doped Ceria (BDC) ionic conductor is prepared by co-precipitation method. Three different samples with different concentrations of boric acid and cerium nitrate were synthesized with ratio B0.3Ce0.70, B0.20Ce0.80 and B0.10Ce0.90 named as BDC-1, BDC-2 and BDC-3 respectively. Sodium carbonate was used as precipitating agent in quantity 20% of total sample. Then fabricated electrolyte was sintered at the temperature 700 ℃ in the furnace. Raman analysis of the electrolyte was conducted to evaluate the vibrational and rotational modes of material. The intense peak showed the vibrational mode of cerium oxide and lower peak showed an oxygen vacancy over some range of 550-650 cm -1 . These results showed that BDC electrolyte have high oxygen vacancies with the increase in sintering temperature. FTIR results showed the formation of the Ce- O bonds, OH stretching, metal-oxide bonds and some residual material peaks. Furthermore, FTIR spectra of the ionic conductor revealed OH stretching indicating that moisture is present in the sample. The conductivity measurements showed that conductivity of BDC-2 was electrolyte 0.086 Scm -1 at 750 ℃. These results revealed that the BDC electrolyte shows high ionic conductivity at intermediate temperatures that makes it useful for SOFC application. Fuel cell performance for BDC electrolyte materials was analyzed by using BCFZ anode and LSCZ cathode and a plot of voltage was drawn. BDC-2 having medium amount of doped Boron achieved high OCV as compared to BDC-1 and BDC-3. It was observed that cerium is best conductor so, its conductive behavior elevates the OCV as compared to Gd and Sm.Item Enhanced Sunlight Photo catalytic Activity and Biosafetsy of TiO2/ZnFe2O4 Nano composites(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Muhammad Noman; CIIT/SP20-RPH-059/LHR; Dr. Akbar Ali; LHR TP 8146A good approach for the photo degradation of Rhodamine B (RhB) dye under UV-Visible irradiation is the use of Titanium di oxide –Zinc ferrites nanoparticles as a photo catalyst, which showed the high photo catalytic activity, highly magnetic reparability and cost-effective results. The nanoparticles of Titanium di oxide-Zinc ferrites (TiO2/ZnFe2O4 x=1 %, 3 %,) were prepared by using hydrothermal synthesis route. The structural and morphological properties of the synthesized nanoparticles studied by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Energy dispersive spectroscopy (EDX), UV-visible spectroscopy, raman spectroscopy and Photoluminescence (PL). The structural morphology showed that prepared samples are uniform. The structural properties confirmed to be in good agreement for both XRD, and SEM results and confirmed the cubical nature of the prepared spinel. Furthermore, the increase in size of the nanoparticles with increase in Titanium di-oxide (TiO2) contents, confirmed from the diffraction peaks and SEM analysis. The size of crystallites ranged in 15.5nm evaluated by using Debye-Sharer‘s formula from more intense diffraction peak. The composition of the prepared specimen confirmed by Fourier transforms infrared spectroscopy (FTIR). Photo catalysis carried out to check the photo catalytic activity of the synthesized nanoparticles having different concentrations of , for the degradation of Rhodamine B (RhB) dye under UV-Visible light. The photo catalytic activity checked, resulted 8%, 27%, 41% and 80% for titanium di- oxide doped zinc iron oxide respectively, for the degradation of Rhodamine B (RhB) dye under UV- Visible irradiation in 0,30,60,90 and 120mins, it is concluded that the photo catalytic activity increased by increasing reaction time and the concentration of titanium di-oxide, and this can be increased up to 80 %. The prepared nanocomposite attested to be cost effective, ecofriendly, reusable after recycling, high magnetic reparability after use, and high photo catalytic activity for the photo degradation of Rhodamine B (RhB) dye under UV-Visible irradiation.Item Enhancement of Structural and Optical Properties of TiO2/ ZnO Thin Films for Solar Cell Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Shahbaz Ul Hassan; CIIT/SP20-RPH-038/LHR; Dr. Shahzada Qamar Hussain; LHR TP 7967DSSCs (dye-sensitized solar cells) are considered low-cost photovoltaic technologies due to their simple manufacturing methods. In this project, titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles were deposited on the Glass based flexible substrate. TiO2 and ZnO nanostructures were synthesized separately by using sol-gel method. Spin coater was used to prepare the TiO2/ZnO thin films on glass substrates. The surface morphology of TiO2 and ZnO was studied using a scanning electron microscope (SEM). The crystallinity and structure of the produced TiO2 and ZnO nanoparticles were investigated using X-ray diffraction (X-Rays). The optical absorption was measured using a UV-Vis spectrophotometer. Dye-sensitized solar cells (DSSCs) were proposed for the ZnO/TiO2/Glass films as the working electrode.Item Up and Down Conversion Nanoparticles, Synthesis, Mechanism for Photovoltaics Application.(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Muhammad Shameer Haider; CIIT/SP20-RPH-005/LHR; Dr. Farah Alvi; LHR TP 7681Fluorescent labelling is a usually utilized critical tool in biology in today's quickly advancing technology. Traditional down conversion fluorescent labels that employ UV or short wavelength light have issues such as fluorescence, low transmission ratio and indirect cell damage to live cells. When irradiated with near infrared light, upconversion nanoparticle release radiation of lower frequency in the near infrared or visible region, a process known as up conversion. They have the most amazing qualities, such as greater photo stability, as compared to existing up-converting materials. They have very low auto fluorescence, no photo harm to living cells, high detection sensitivity and a great depth of photon penetration, overcoming some of the shortcomings of standard down conversion labels, making it a suitable fluorescent label for bio imaging. They avoid some of the drawbacks of traditional down conversion labels by offering benefits such as very low fluorescence, no phototoxicity to live cells, excellent detection sensitivity and a great depth of photon penetration, category to them a suitable fluorescent for bio imaging. Upconversion nanoparticles are being changed in a variety of ways to make them more hydrophilic and biocompatible. Because of these advantages, upconversion nanoparticles could be used in immunoassays, bio imaging and PD. Because of their enormous size, lack of organic compounds for biological conjugation, and instability in aqueous solutions, upconversion nanoparticles can yet be improved. Co-doping between two distinct lanthanides ions, one behaving as an absorber and the other as an emitter, is commonly used to improve upconversion nanoparticles by utilizing the energy transfer mechanism. The spectrum features of the system NaYF4 doped with Er3+ and Yb3+ with an increased electromagnetic field will be studied in this work. As a spacer, silica will be utilized and characterization will be done using conventional optical techniquesItem Development of Chitosan Hydrogel Membrane Incorporated Au Doped SnO2 Nanoparticles for Antibacterial Activity and Wound Healing Application(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Momina Rehman; CIIT/SP20-RPH-010/LHR; Dr. Muhammad Hammad Aziz; LHR TP 7709Metallic nanoparticles are well known for their biomedical applications including antimicrobial activity and wound dressing materials due to large surface to volume ratio and other chemical properties. In this work, gold doped tin oxide (Au-SnO2) nanoparticles containing chitosan-based porous membranes were prepared by the freeze-gelation method. Hydrogel membranes were prepared using the blending of natural polymers and loading metallic nanoparticles as an antibacterial agent. The different membranes were prepared using the different concentrations of metallic nanoparticles by the freeze-gelation process, during this process Triethyl Orthoformate (TEOF) used as a cross-linker agent. This different concentration of membranes were tested for bactericidal potential using the disk diffusion method. Further, swelling studies of these membranes were performed in PBS solutions. The presence of Au-SnO2 NPs were confirmed by the scanning electron microscopy (SEM) analysis. The Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed the presence of the chitosan functional group. All these experiments confirmed that these membranes are safe to use for wound dressing material and other biomedical applications.Item A Study of Structural properties of Porous ZeoliteImidazole Based 2-Dimensional Nanostructures For Electrochemical Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Nadir Ali; CUI/SP20-RPH-055/LHR; Dr. Farah Alvi; LHR TP 7701Recently, 2-D metal oxide frameworks (MOFs) have exhibited great potential for energy storage devices including supercapacitors and batteries. This is due to their superior and highly tunable porous, structural, and morphological features. Zeolite imidazolate frameworks (ZIFs) are highly chemically, and thermally stable class of MOFs which offer a wide variety of tunable porous structures and morphologies in comparison to widely used nano porous carbon which requires inert gas environment and high temperature treatment for large scale production and is therefore hazardous and expensive. In this work, facile and one-step environmentally friendly synthetic routes will be investigated and implemented for tuning of ZIF-67 derived porous nanostructures as electrode materials for renewable energy storage applications. The structural properties of the developed novel materials will be investigated using RAMAN spectroscopy measurements and analysis. The porosity of the materials will be estimated using Brunauer–Emmett–Teller (BET) surface area analyzer. The variation in morphology, pore size and structure will be studied by analyzing the shift in Raman vibrational modes of the samples.Item Tuning the Catalyst Materials in Anode to Improve the Electrochemical Properties of Low Temperature Solid Oxide Fuel Cell(LHR TP 7695, 2021) Omer Abbas; CIIT/SP20-RPH-047/LHR; Dr. Ghazanfar Abbas; LHR TP 7695In present study zinc-based anode materials with composition Ba0.10Cu0.20M0.10Zn0.60 oxide (where M represent Mn, Mo, and Ag) were synthesized via cost effective sol-gel technique. The effect of suggested M components was observed to understand the electronic conduction mechanism with the diffusion of the hydrogen ion. In this work, materials synthesized by sol-gel technique and their functionalities are investigated as an anodic function of solid oxide fuel cell (SOFC). Their investigations consist of various characterizations such as Fourier Transformation Infrared Spectroscopy (FTIR), Raman Spectroscopy, X-ray diffraction (XRD) and Electrochemical Impedance Spectroscopy. FTIR technique is employed to analyse the chemical composition and its bounding. The Ba0.1Cu0.2Ag0.1Zn0.6O show that the peaks at 667 cm-1 738 cm- 1, 1121 cm-1, 1331 cm-1, 1664 cm-1, and 3238 cm-1 belong to Zn-O vibrational energy bond, the vibrational bond of C-O (symmetric) of ZnO, Zn-O stretching bonds and O-H hydroxyl group, respectively. The Ba0.1Cu0.2Mo0.1Zn0.6O show that the peaks at 675 cm-1 762 and 1339 cm-1, 1042 cm-1, 1121 cm-1, and 3010 cm-1are associated with the O-H bond, C-O bond, and C-H group, respectively. The Ba0.1Cu0.2Mn0.1Zn0.6O show that the peaks at 667 cm-1 754 cm-1, 875 cm-1, 1323 cm-1, 1113 cm-1, and 3644 cm-1 belong to Mn-O stretching bond, Zn-O vibrational energy, Zn-O bond, Zn-N bound bond, and O-H hydroxyl group, respectively. Raman spectroscopy is used to detect vibrational, rotational, and other states in a molecular system, capable of probing the chemical composition of materials. The Ba0.1Cu0.2Ag0.1Zn0.6O Raman pattern that the peak at 431 cm-1 belong to E2 High-E2 LOW mode of Zn-O, at 135 cm-1 peak associate to E2 High mode of Cu-O, and at 577 cm-1 relate to Cu-O, at 1144.54 cm-1 and peaks 1071 cm-1 related to AgO, and 1144 cm-1 linked to multi-phonon scattering process. The The Ba0.1Cu0.2Mo0.1Zn0.6O Raman pattern that the peaks observed at 135 cm- 1, 325.76 cm-1 for Cu-O and MoO, 577.18 cm-1 belongs to Cu-O, Zn-O at 435.3 cm-1 and 792.4, 837.4,8.889 and 1149 cm-1 relate to Mo-O bond. While, at 1149 cm-1 peak associate to the glass substrate. The Ba0.1Cu0.2Mn0.1Zn0.6O Raman pattern that the peaks at 337 cm- 1, 432 cm-1 belong to Zn-O mode of E2 high-E2 low, and E2 high, respectively. A peak at 659 cm- 1 belongs to the Mn-O group. While, at 964 cm-1 peak associate to the glass substrate, but at 1164 cm-1 is C-H group. X-ray diffraction used to calculate the crystal phase, cell parameter, volume, and density of a material. The Ba0.1Cu0.2Ag0.1Zn0.6O XRD pattern describes that oxide materials have composite nature consist of three-phase structures, where the phase of Zn-oxide (hexagonal structure, JCPDF 01-079-2205) may be in-cooperated with the phase of BaAg6O4 (orthorhombic structure, JCPDF 01-71-0749) and Cu-oxide (monoclinic structure, JCPDF 00-048-1548). The average crystallites sizes were found to be 85.2 nm, 96 nm, and 63.67 nm, respectively. The XRD pattern of Ba0.1Cu0.2Mo0.1Zn0.6O describes that oxide materials have composite nature consist of three-phase structures, the Cu-oxide (monoclinic structure, JCPDF 00-048-1548), BaMoO4 phase (tetragonal structure, JCPDF 00-008-0455), and Zn-oxide (hexagonal structure, JCPDF 01-079- 2205). The average crystallites sizes were found to be 78.45 nm, 65.63 nm, and 85.46 nm, respectively. The XRD pattern of Ba0.1Cu0.2Mo0.1Zn0.6O revealed that oxide materials have a three-phase structure, Zn-oxide (hexagonal structure, JCPDF 01-079-2205) is maybe in-cooperated with the phase of BaMn8O16 (tetragonal, JCPDF 00-029-0188) and Cu-oxide (monoclinic structure, JCPDF 00-048-1548). The average crystallites sizes were found to be 71 nm, 64 nm, and 57.6 nm, respectively. The Electrochemical properties were investigated by AC Electrochemical Impedance Spectroscopy (EIS) technique by 4-probe method under air and hydrogen atmosphere. The materials show the increasing behavior, with enhancing the temperature, which describes the nature of semiconductors and performance work of SOFC is under processItem Fabrication and Characterization study of Micro Thin Film Electrolyte for the Solid Oxide Fuel Cell (SOFC)(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) RIZWAN ASGHAR; CIIT/SP20-RPH-033/LHR; Dr. Muhammad Ajmal Khan; LHR TP 7691In this study, Calcium Doped Ceria (CDC) thin film is prepared by the two steps, in the first step calcium doped ceria (CDC) powder is synthesized by co-precipitation method and in the second step, the slurry of calcium doped ceria (CDC) with ball milling and then thin film is casting with help of Tape casting technique. The fabricated thin films were sintered in the range of temperatures (150-750) ℃, in an air atmosphere. Crystal structure revealed that thin film has a cubic fluorite structure, and its average crystallite size is in the range of (53-42) nm. Raman analysis of the thin film was done in the temperature range of 350-750℃. These results showed that CDC thin films have high oxygen vacancies as sintering temperature rises. Which was depicting the high conductivity of the thin film. These results were also verified by the Conductivity measurements. The increase in FWHM of main peaks of Raman spectra, with an increase in temperature resulting in reduction of the crystallite size. Which was also confirmed by XRD results. FTIR results showed the formation of the Ce-O bonds, OH stretching, etc. Furthermore, FTIR spectra of the thin film at various temperatures indicated that OH stretching decreased as temperature increased, indicating that moisture in the sample reduced. Uv visible analysis was done at two different temperatures, 150 and 750℃. Band gap values decreased with increase in the temperatures. It was 3.22eV at 750oC and 3.3eV at 150℃. The conductivity measurements showed that conductivity of thin film was increasing as sintering temperature rises. which was confirmation of Raman results. Thin-film showed the highest conductivity 0.052 Scm-1 at 750℃, the activation energy and electrical band gap calculated from the Arrhenius plot are 0.25 eV and 0.5 eV for the sample sintered at 750oC, respectively. EIS spectra thin-film sintered at 750℃ and 150℃ showed semicircle, which confirms the ionic behavior of the CDC electrolyte thin film. The ohmic resistance also decreased with an increase in the sintering temperature. These results revealed that the thin film shows high ionic conductivity at intermediate temperatures. Which makes it useful for SOFC application.Item Composition-Structure-Property Correlations in Lanthanide Doped Oxide Glasses(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Tayyaba Akram; CIIT/SP20-RPH-018/LHR; Dr. Junaid Amjad; LHR TP 7712Rare earth pyrophosphate-based glass materials show promise for optical, photonic, and biomedical uses. In this study, Dy3+ ions and TiO2 were co-doped in pyrophosphate glass, and new glass with varied characteristics was created using the melt-quenching approach. The intensities of rare earth 4f intrabank transitions changed when metallic titanium nanoparticles (NPs) were added. Ti plasmonic nanoparticles impact photoluminescence spectroscopy of pyrophosphate glass co- doped with Dy3+ ions. Advanced techniques, such as Raman, PL (photoluminescence), and FTIR, are used to study the optical characteristics of these glasses. The results demonstrate absorption and luminescence spectroscopy, as well as the excited state lifetime, which influences the optical characteristics of the glassItem Up Conversion and Down Conversion Nanoparticles for Nano Medicine, Synthesis, Surface Modification, and Biological Applications.(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Muhammad Sajjad Farid; CIIT/SP20-RPH-008/LHR; Dr. Akbar Ali; LHR TP 7683Upconversion nanoparticles (UCNPs) and down conversion nanoparticles (DCNPs) have outstanding optical characteristics and are used in a variety of disciplines such as photonics, energy and material design. They describe the mix, material, and optical characteristics, as well as the functionalization of various UCNPs and DCNPs, before focusing on continuing advancements in using usable UCNPs and DCNPs. Because it reduces the heat of biological cells given by 980 nm excitation light, the upconversion luminescence (UCL) of rare earth ions doped nanoparticles stimulated at 808 nm is more acceptable for biological applications than the UCL of rare earth ions doped nanoparticles excited at 980 nm. On the other hand, one of the major challenges to greater UCL application is the poor UCL efficiency of rare earth ions doped nanoparticles activated at 808 nm. There is a problem with rare earth UCNPs that they suffer from low up conversion efficiency and gives quantum yield of maximum 1% because they have small cross section for the absorption because of 4f-4f transition is not allowed by the mean of selection rules so, they are inefficient for practical implementation in a significant number of situations. Thus for the time being, the -NaYF4 will be used as a host material, which is chemically and optically stable and its optical transparency lies in our range of spectra and its co-doped with lanthanides Yb3+ and Nd3+ provide us the highest quantum yield. In this study, the amount of dopants Nd3+ will be kept fixed whereas Yb3+ concentration will be changed from 0-0.98g. Thus in this research proposal we will use NaYF4 host matrix and Yb3+ and Nd3+ will be used as dopants to study the down conversion emission enhancement. The spectroscopic techniques will be used to analyze for prepared geometry.