Department of Chemistry
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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 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 MXene Coated Carbon Cloth as Flexible Electrode in Supercapacitor Applications(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Maryam Gull; FA22-R06-007; Dr. Sara Riaz; LHR TP 9311Due to the rising need for energy brought on by industrialization and population increase, the globe is currently experiencing an energy crisis. Utilizing fossil fuels to meet this need results in environmental pollution and greenhouse gas emissions that fuel global warming. Though they are not reliable sources of electricity, the use of renewable energy sources including the sun, wind, and water has increased. As a result, the supercapacitor, an energy storage device, has become more well-known because of its long-life cycle, high cycling stability, and environmental safety. Compared to batteries, supercapacitors and flexible supercapacitors offer a significantly better power density. Flexible supercapacitors can be operated using the same fundamental ideas as conventional capacitors. Nonetheless, flexible supercapacitors surpass conventional capacitors in terms of capacitance due to their greater charge storage, remarkable flexibility, and reduced resistance. That’s why, an electrode material with exceptional cycle stability and enhanced power and energy density is fabricated. In present work, MXene modified with Yb-MOF. The prepared material was analyzed by XRD, FTIR, SEM, UV, and Raman spectroscopy. Electrochemical activity was investigated using GCD, EIS, and CV, covering the carbon cloth with the electrode active substance. The material that was successfully synthesized has high energy and power density, as well as outstanding cyclic stability, as demonstrated by results.Item N/S Co-Doped Graphdiyne as an Electrode Material for Supercapacitor Applications: A Computational Study(Library Information Services, COMSATS University Islamabd, Lahore Campus, 2025) Aqsa Naz CIIT/FA23-R06-005/LHR; Dr. Sara Riaz; LHR TP 9683The need for efficient and sustainable energy storage systems has increased due to the world's growing energy consumption and the depletion of fossil fuel supplies. Supercapacitors have attracted a lot of interest because of their remarkable power density, quick charge and discharge rates, and extended cycle life, which make them ideal for uses like grid stabilization and electric vehicles. Supercapacitor electrodes are often made of carbon-based materials, particularly two-dimensional (2D) frameworks, because of their large surface area, adjustable electrical characteristics, and strong chemical stability. In this study, a comprehensive first principle study was used to examine the potential of graphdiyne (GDY), a 2D carbon allotrope made up of sp- and sp²-hybridized carbon atoms, as an electrode material for supercapacitors. This study investigated nitrogen (N) and sulphur (S) doping and co-doping at different locations. Stability of doped structures was determined based on formation energies and cohesive energies. Pristine GDY exhibited a large band gap (3.52 eV) and low density of states (DOS) near the Fermi level, it shows that GDY has limited intrinsic conductivity. Doping with N and S significantly reduced the band gap. The chemical hardness was also reduced, accompanied by an increase in electrophilicity, it indicates improved reactivity and charge storage capability. Electron Localization Function (ELF) analyses revealed balanced regions of localized and delocalized electron density, with intense localization at heteroatom sites in co-doped structures, it indicates efficient charge trapping and transport. Charge Density Difference (CDD) maps further confirmed substantial charge x redistribution around dopant atoms, indicating enhanced active sites for ion adsorption. Density close to the Fermi level was revealed by Density of States (DOS) analysis, and this is directly correlated with better quantum capacitance. DOS plots showed a marked increase in states near the Fermi level for co-doped systems, directly correlating with enhanced quantum capacitance and electrochemical performance. These findings highlight the potential of heteroatom- doped GDY structures, particularly co-doped configurations, as high-performance supercapacitor electrode ma terials, paving the way for next-generation sustainable energy storage technologies.Item Preparation of Hydrogel-Based Electrolytes for Flexible Supercapacitor Electrodes(2025) Sunaina Ahmad CIIT/FA23-R06-024/LHR; Dr. Sara Riaz; LHR TP 9695Energy plays a crucial part in every aspect of modern life, because of the traditional energy storage devices as well as the problem regarding endurance, the small and flexible energy storage devices are more widely used in recent times. Supercapacitor is an energy storage device with advanced applications, like specific capacitance, environmental friendliness, charging and discharging properties, extensive life-span power and energy densities. Conventional SCs used liquid electrolytes which were toxic and cause leakage in SCs. Researchers choose safer options by using hydrogel electrolytes. Hydrogels are three-dimensional network of polymer with incorporation of liquid molecules, hydrogels are leakage proof, electrochemically stable, less toxic and highly biocompatible. The performance of SCs was enhanced using gelatin and polyvinyl alcohol and ratios of polyphenols from green tea extract and potassium hydroxide. Hydrothermal method was used to prepare electrode material of core shell (ZIF8/ZIF67). Synthesis of hydrogel electrolytes was done by incorporating borate crosslinkers with polyvinyl alcohol and gelatine. Series of hydrogel electrolytes were synthesized, with different quantities of polyphenols. FTIR, contact angle and XRD techniques were performed to study hydrogel electrolytes. Then, by incorporating two electrodes and an electrolyte, a supercapacitor device was fabricated. To analyze the efficiency of the supercapacitor, GCD, CV, and EIS were performed.