M.Phil / MS

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This collection archives the complete set of theses produced by students of the COMSATS University Islamabad, Lahore Campus.

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Boosting the Electrochemical Activity of BSMO Cathode by Compositing (Sm0.20Ce0.50Bi0.30)2O3+δ for Low Temperature Solid Oxide Fuel Cell
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Muhammad Amir; CIIT/SP24-RPH-006/LHR; Dr. Ghazanfar Abbas; LHR TP 10120
Among energy conversion devices solid oxide fuel cells (SOFCs)are promising candidates due to their fuel flexibility and highly efficient; though, but their commercial application is limited due the high temperature. In this research work barium and strontium based low temperature solid oxide fuel cells (LT-SOFCs) were fabricated and characterized as cathode material for LT-SOFCs. Solid state method was adopted to synthesize barium strontium manganese oxide (Ba₀.₇₅Sr₀.₂₅MnO)₃−δ (BSMO) and (Sm₀.₂₀Ce₀.₅₀Bi₀.₃₀)₂O₃+δ (SCBO) was synthesized via the reverse co-precipitation route. The crystallographic crystal of the synthesized material was analyzed by employing XRD and all the samples shows highly crystalline structure. The characteristic vibrational modes of Sm-O, Ba–O, Ce-O, and Mn–O were confirmed from Raman spectroscopy. The BSMO, SCBO and BSMO/SCBO composite were fabricated via solid state mixing and electrochemical impedance spectroscopy (EIS) spectroscopy measurements were recorded with in the temperature range 400oC-700oC and enhanced electrochemical characteristics of the SCBO material was observed. It was observed that the BSMO/SCBO composite exhibited lower polarization resistance compared to pristine BSMO and SCBO within the temperature range of 550°C –650 °C, that results the improved ionic–electronic conductivity balance and enhanced charge transfer. DC conductivity measurements showed the semiconducting behavior of BSMO material and reduce and stable conductivity for SCBO, and intermediate conductivity value of conductivity for the composite material. All samples show the high open circuit voltage value (1.05 V) at 650 °C. The Fourier transfer Infrared (FTIR) spectroscopy was employed to study the functional groups. The results shows that the synthesized novel BSMO, SCBO and their composites can be the efficient materials for the future low temperature SOFCs applications.
Hybrid Ion Conductors Membrane for CO2 Separation
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2018) TAUQEER AHMAD; SP16-RPH-028; LHR TP 5246; Dr. Ghazanfar Abbas
CO2 is emitted in a very large amount per year by the different fossil fuel industries for the generation of energy which is the major origin of GHG in the climate. CO2 emission is a major worldwide problem of today. Different works have been done for the reduction of CO2 emission gas and numerous types of works are under process. In our project the major focus is to separate the CO2 by hybrid ion conductors membrane of solid oxide fuel cell. For this purpose, GDC/Li2CO3-Na2CO3 (LN-GDC) nanocomposite electrolyte material was synthesized with molar ratio 1:3 by co precipitation method. The sample was dried in oven and filtered by suction pump followed by sintering at temperature 700oC in a digital furnace. The prepared sample LN-GDC was further characterized by different techniques; XRD, SEM, FTIR including conductivity measurements by four probes DC method. The XRD and SEM results confirm that the synthesized material lies in nano scale, homogeneous and dense in nature. However, the major study was focused to analyze the CO2 separation from this membrane so the sample was further reformed in polymer membrane and chloroform was used as a solvent for the preparation of dense hybrid membrane. This modified prepared hybrid membrane is used for the separation of CO2 gas
Investigation of Divalent/Trivalent Metal Doping into SrFeO3 as a Cathode Material for Low Temperature SOFC
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Tariq Aslam; CIIT/SP23-RPH-011/LHR; Dr. Ghazanfar Abbas; LHR TP 9632
In this research, I have prepared cathode for low temperatures solid oxide fuel cells. Divalent (Ba, Mg) and Trivalent (Co, Al) were mixed in strontium ferrite oxide materials. Mixture of these samples were dried at 200℃ for 150 minutes in oven for its dehydration. Then, samples were passed through sintering process at 750℃ for 4 hours. Due to sintering at high temperature, our samples become dense, its many properties were changed at large temperature like, increase its mechanical strength of Nano materials, and boost up its bond strength and also material become homogeneous and stable. Fabricated material were characterized by UV- Visible spectroscopy, FTIR (Fourier transform infrared), and Raman Analysis. FTIR technique was set peaks at transmission of light with wavelength 400cm-1 and 4000 cm-1. FTIR peak at 1017 cm-1 indicate Fe–Ba–O bonds, carbonate groups and hydroxyl groups present at peak1453 cm-1 and 1642 cm-1 respectively, while 2834 to 2980 cm-1 peaks were denoted the CH2 and CH3 acetate formation. UV-visible is analytical technique which was proceed the data about sample composition, structural properties of the nano particles when light was transmitted in the materials at diverse wavelength. By Tuac plot of UV-visible we have calculated the band energy gap value Ba metal in SrFeO3 materials was measured 2.80eV, Eg of Al was 2.66 Ev. These energy values are required to excite the electrons form VB to CB to make the material conductive. Raman spectra illustrate the orthorhombic and FeO₆ octahedral structure at peaks ranges 123 to 664 cm⁻¹, tells about vibrational modes and presence of of oxygen vacancies, this show that more oxidation reduction reaction phenomena occur.
Alkaline Metal Coated Nanostructured Doped Ceria Electrolyte For Low Temperature SOFCs
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Bushra Mumtaz; CIIT/FA22-RPH-017/LHR; Dr. Ghazanfar Abbas; LHR TP 9431
In this study, electrolyte was fabricated for solid oxide fuel cells. Alkaline (Ba, Ca, Sr) coated samarium doped ceria and gadolinium doped ceria electrolyte for solid oxide fuel cell was prepared successfully. All of these samples were prepared by co- precipitation method. These materials give better results and produce more oxygen ions vacancies which enhance the oxidation reduction reaction. The synthesized material characterized by using Raman Spectroscopy, Uv-Vis spectroscopy, X-ray diffraction and Electrochemical Impedance Spectroscopy. Raman spectra show vibration modes and the structure of materials particles. Raman analysis of samples was done from 700- 900 °C. These results showed the strong peak of cerium oxide in range of 450 to 470nm and the weak intense peak representing oxygen ion vacancies. It tells about which type of shifting occurring in prepared material. In all prepared materials, there is blue shifting and wavelength is decreasing which show that particles size is decreasing. In UV-Vis spectroscopy result demonstrated the band gap values which ranges from 1eV to 2.5eV. With the help of XRD compositions and structure was confirmed, which is found to be cubic. EIS tells about the ionic and electronic behavior of materials. EIS tells about ohmic resistance, polarization resistance and total resistance of the material. EIS tells about charge transfer and mass transfer in material. The conductivity of materials can be calculated with the help of EIS, which is found to be 0.005Scm-1 at 550°C.
Tuning the Ionic Conductivity of Electrolyte Material to Optimize/Enhance the Solid Oxide Fuel Cell Performance
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Nabgah Tariq; CIIT/SP22-RPH-008/LHR; Dr. Ghazanfar Abbas; LHR TP 8779
The world is using up non-renewable energy sources quickly. Fossil fuel-based energy supplies may run out in a century and two decades. Fossil fuels have many harmful effect on human health and environment. Although fuel cell have received a lot of interest because there great efficiency, simplicity, low impact on the environment, cost effective and fuel adaptability. All fuel cell types, solid oxide fuel cells (SOFCs) is gaining more popularity. Ba-SDC, Sr-SDC, Ca-SDC & Ti-SDC was used as an electrolyte improve properties of solid oxide fuel cell. Due to this purpose electrolyte material was synthesized by co-precipitation method. Prepared material analyzed by various technique such as Raman, UV-Visible, Fourier transform infrared spectroscopy, Conductivity measurement & Open circuit voltage (OCV). Raman sample expose strong peak between 600cm-1 to 1200 cm-1, which may be predict the vibration mode and change in structure. It describes the kind of shifting that occur in prepared material. The presence of blue shift in material may be shows heavy atoms in material by which its bound length got shorter and the red shift predict bound length increase by increase by wavelength also it shows the active modes (F1g, A1g and Eg). By UV-visible, synthesized sample's band gap and absorbance are detected. FTIR provides information on the presence of functional groups in materials as well as the organic or inorganic behavior of manufactured materials. With the aid of temperature dependent EIS, the conductivity of materials may be computed. Ti-SDC shows maximum conductivity at 700°C and having value 0.090 S/cm. Using hydrogen as fuel improves the conductivity of materials by utilizing fuel cell performance at temperatures ranging from 500°C to 700°C.
Investigation of the Electrochemical Effect of Rare Earth Materials on Zinc based Anode for SOFC
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) ATIF HAYAT; CIIT/FA20-RPH-043/LHR; Dr. Ghazanfar Abbas; LHR TP 7999
Current scenario of the energy requirements motivates to researchers to explore the renewable energy resources. This also will be helpful to control the climate environmental issues to save the future. Fuel cells have aroused a lot of interest in this activity because of their high conversion efficiency when compared to traditional energy conversion approaches. Because of its low hazardous emissions, pollution, fuel adaptability, and cost-effective components, SOFCs are importance source for energy conversion technologies. Some issues are still need to be addressed, as conventional SOFC works at high temperature but the fact is that the SOFC activity reduces at low temperatures due to interfacial polarization blockages and the oxygen reduction process. In this context, in the present study zinc- based anode materials with composition Ce0.2(Zn0.5 Ni0.5)0.8, Sm0.2(Zn0.5 Ni0.5)0.8, Gd0.2(Zn0.5 Ni0.5)0.8 were synthesized via cost effective sol-gel technique. The effect of rare-earth materials has been investigated in terms of electrochemical properties. Their investigations consist of various characterizations such as Fourier Transformation Infrared Spectroscopy (FTIR), Raman Spectroscopy, UV-Vis, EIS, and fuel cell performance. FTIR is employed to analyse the chemical composition and its bounding. The FTIR spectrum the band at 1082 cm-1 can be attributed to the O- Ce-O stretching mode of vibration. The FTIR spectrum of zinc oxide nanoparticles absorbs at 648.50 cm−1. The absorption bands in the range of 743 cm−1 correspond to Ni-O stretching vibration mode. The large broad band at 3415cm-1 is ascribe to the O-H stretching vibration in OH groups. Raman spectroscopy is used to detect vibrational, rotational, and other states in a molecular system, capable of probing the chemical composition of materials. The Ce0.2(Zn0.5 Ni0.5)0.8 Raman pattern that the peak at 450-460 cm-1 attributed to Raman-active F2g mode of fluorite-structured CeO2. The Electrochemical properties were investigated by AC Electrochemical Impedance Spectroscopy (EIS) technique by 4-probe method under hydrogen atmosphere. The materials show the increasing behavior of conductivity with increasing the operating temperature. UV-visible characterization technique held to examine the optical properties of the sample and used to get the absorbance and reflectance spectra under the selected UV range of 190-800 nm. The fuel cell performance was carried out by making three –layers cell and maximum OCV was obtained 0.53V of Ce(NiZn) material.
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 7965
In 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.
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 7695
In 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 process
To investigate the Effect of Alkaline Earth Metals on Electrochemical Activities of Lanthanum Cobalt Zinc Oxide Cathode Materials
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) AQIB RAFIQUE NOORI; CIIT/SP20-RPH-024/LHR; Dr. Ghazanfar Abbas; LHR TP 7966
In the modern age of science and technology every system of manual work is transferring to machines and to run these machines energy is required, so the need of time is motivating researchers to enhance their activities in the scope of renewable energy production devices which will be able to produce more energy at very low cost. In this regard fuel cell got higher attraction of investigation due to its higher efficiency, environmentally friendly nature, and low cost. Solid oxide fuel cell (SOFC) is an extremely encouraging class of fuel cells. SOFC consists of electrolyte sandwiched between anode and cathode. In this research work, lanthanam-based cobalt Zinc oxide cathode materials are prepared by sol-gel route alongwith the characterizions for the cathode functioning of solid oxide fuel cell (SOFC). FTIR technique is employed to analyse the chemical composition and its bounding. In BaLaCoZn peaks are found at 853 cm -1 ,859 cm -1 and 1426 cm -1 which are corresponding to C-O, La-O and Co-O respectively. In CaLaCoZn peaks are found at 703 cm -1 , 988 cm -1 , 1433 cm -1 which are attributed to Zn-O, C-O,Co-O, respectively. In SrLaCoZn peaks are observed at 856 cm -1 , 950 and 1441 cm -1 which belong to Sr-O, Zn-O respectively. For Sr1Co0.8La0.2 (SCL) peaks are found at 157 cm -1 , 525 cm -1 , 957 cm -1 and 1363 cm -1 . The analysis of existence of each and every C-H, C-C, C=C, O-H either of bending or stretching nature is given in following table against each wave number in each sample. In infrared spectroscopy, there are basically two regions, fingerprint region and functional groups region. The range of fingerprint region is from 400 cm -1 to 1500 cm -1 wave number which is not analyzed usually due to its complexity, as a large number of peaks appears in that region. Each bond represents existence of a functional groups. The prepared cathodes have strong peaks in the range of 700 cm -1 to 1800 cm -1 .The peaks are attributed to C-H, C=O, O-H and C=C which are the main bonds present in oxides base cathodes. Raman spectroscopy is used to detect vibrational, rotational, and other states in a molecular system, capable of probing the chemical composition of materials. For samples BLCZ (S1) peaks are found at 157, 525, 957 and 1363 cm -1 . The peaks at 157 and 525 cm −1 wavelengths are analogous to O-B-O typical vibrations. The peak at 957 cm −1 wavelength correspond to B-O bonds stretching vibrations. For samples SLCZ (S3) peaks are found at 141, 296,649, 939, 1086 and 1344 cm -1 . The peaks at 141, 296 and 649 cm −1 wavelengths are analogous to O-B-O typical vibrations. The peaks at 939 and 1086 cm −1 wavelength correspond to B-O bonds stretching vibrations. Furthermore, for the Raman spectra of single Perovskite LSCF there is no mode vibrations in the range of 200–500 and 700–900 cm −1 can be found except (S2), which are xi demonstrative of double Perovskite structures LSCF materials. Therefore, the outcomes of the Raman spectral study agree well with those of literature, which showed that both the rhombohedra structure and double Perovskite phase are from space group R3C. So S1, S2 and S3 will behaves as an excellent cathode material as generating more oxygen ion vacancies which enhance the oxygen reduction reaction (ORR) at the cathode side. The electrical DC conductivity of prepared cathodes BaLaCoZn, CaLaCoZn and SrLaCoZn were measured by two probe method in the temperature range of (300-600) o C in the presence of methane as a fuel in air environment. The synthesized cathode material (S1) has maximum conductivity of 10.12 Scm -1 at 600 °C and the synthesized cathode material (S2) has minimum value of 3.3 Scm -1 at 300 °C.
Approaches Towards Boosting the Ionic Conductivity of Electrolyte Materials for Low-Temperature Solid Oxide Fuel Cells
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) SARFRAZ; CIIT/SP20-RPH-051/LHR; Dr. Ghazanfar Abbas; LHR TP 7698
BaZr1−X GaX O3−δ (where x=0.1, 0.3 and 0.5) electrolyte materials for solid oxide fuel cell (SOFC) are synthesized in this research project. Cost effective co-precipitation, solid state reaction, and sol-gel methods are used to synthesize the electrolyte materials for SOFC. All the materials are sintered at low temperature (800℃) and low sintering effect also is discussed. Crystal structure, element composition and functional group are studied by XRD, FTIR and RAMAN spectroscopy. XRD confirms the peroveskite based cubic structure with Pm3m space group. The crystallite sizes are calculated in the range of 29.67 - 15.37 nm. FTIR and Raman analysis confirm the functional groups, stretching and bending modes. The maximum conductivity of BZG was recorded to be 0.065 S/cm at 750 ℃ (when x = 0.1 via co- precipitation).

M.Phil / MS

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