Yazar "Shahzad, Ayesha" seçeneğine göre listele

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    Construction of rectangular microporous Cerium 3D metal organic framework for high performance energy storage devices
    (Academic Press Inc Elsevier Science, 2025) Shahbaz, Muhammad; Sharif, Shahzad; Afzal, Tayyaba Tur Rehman; Shahzad, Sundas; Shahzad, Ayesha; Sahin, Onur; Bentalib, Abdulaziz
    In modern era, there is a dire need to design a hybrid energy storage device showing properties of both supercapacitors and batteries. No doubt, various electrode materials have claimed their efficiency but metal organic frameworks (MOFs) have been focused significantly due to their salient features like high porosity and unique electrochemical properties. In this article, we report cerium-based 3D MOF having rectangular microspore sizes 0.27 x 0.52 nm for rapid and selective transport of charges to be used in hybrid energy storage devices. Structural elucidation was carried out thought single-crystal X-ray diffraction (XRD) spectroscopy and electrochemical attributes were delved via different electroanalytical tools. Three-electrode assembly in 1 M KOH electrolyte unearthed efficiency of the synthesized material and practical applications were divulged through two-electrode assembly by fabricated hybrid device. Diffusive and capacitive contribution of the material was investigated by Dunn's method. The hybrid device showed specific capacityof 101.3 C/g, specific energy of 21.11 Wh/kg and specific power of 1237.78 W/kg with cyclic stability of 99 % even after 5000 GCD cycles. Significant results proved that the material is a prospective contender for futuristic hybrid supercapacitors.
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    Enhanced electrochemical performance of cerium-based metal organic frameworks derived from pyridine-2,4,6-tricarboxylic acid for energy storage devices
    (Elsevier, 2024) Shahbaz, Muhammad; Sharif, Shahzad; Shahzad, Ayesha; Sahin, Zarife Sibel; Riaz, Bilal; Shahzad, Sundas
    Modern era demands development of hybrid supercapacitor amalgamating characteristics of battery and supercapacitor is a single unit. Various contender electrode materials have been used so far, however, metal organic frameworks, having rich porosity and distinctive electrochemical properties can be integrated in energy storage devices to improve electrochemical performance. Herein, we have synthesized Ce-PTA-MOF from pyridine-2,4,6-tricarboxylic acid which was structurally as well as electrochemically characterized. Effects of different concentrations of KOH electrolyte on electrochemical properties of Ce-PTA-MOF electrode has been investigated using three electrodes assembly and practical applications of hybrid supercapacitor device has also been explored by fabricating it with activated carbon. The stability and capacitive-diffusive contributions of the hybrid supercapacitor has been analyzed by theoretical approach. The specific capacity, maximum energy density and power density were calculated as 115 C/g, 26.75 Wh/kg and 5760 W/kg respectively which showed efficiency of 99.2 % even after 5000 GCD cycles. High energy density and power density with extraordinary stability make Ce-PTA-MOF electrode a promising candidate for futuristic hybrid supercapacitor devices.
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    Nitrogen and sulfur-rich cobalt complex for hybrid supercapacitor applications
    (Elsevier, 2025) Saeed, Maham; Shah, Javed Hussain; Sharif, Shahzad; Shahbaz, Muhammad; Ullah, Ghulam; Shahzad, Ayesha; Sahin, Zarife Sibel
    In the quest for more effective and advanced energy storage devices, an integrated methodology combining both battery and supercapacitor hybrid features is being explored. In this regard, we have developed a cobalt-1,10-phenonthroline complex with 5-sulfoisopthalic acid in the lattice (Co-Phen@SIP) via sonication method. Structural properties were explored by Single-crystal XRD, Elemental analysis, TGA, FTIR, UV Visible and Fluorescence spectroscopy while detailed electrochemical study was carried out via CV, GCD and EIS. Three electrode setup revealed pseudocapacitive properties of Co-Phen@SIP with specific capacity of 157.6 Cg(-1) at 2 A g(-1). Battery-supercapacitor hybrid device showed energy density and power density of 13.03 Wh kg(-1) and 3309 W kg(-1) respectively. The device also exhibited remarkable columbic efficiency of 98.94 % even after 5000 GCD cycles. Theoretical approach based on Dunn's model and power law was also applied to check the capacitivediffusive contributions of three-electrode system and hybrid device. 1, 10-phenonthroline induces structural stability over long cyclability. The introduction of SIP in Co-complex caused charge transfer through pi center dot center dot center dot pi interactions providing porous and robust structure which aided in improved electric conductivity and ionic mobility. This multi-ligand chemistry with the redox active cobalt has achieved superior performance and reversibility in comparison to other traditional complexes. The idea came out to be an effective strategy for advanced hybrid supercapacitors.
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    Structural, DFT and redox activity investigation of 2D silver based MOF for energy storage devices
    (Elsevier Science Sa, 2024) Sharif, Shahzad; Shah, Javed Hussain; Shahbaz, Muhammad; Riaz, Bilal; Shahzad, Sundas; Shahzad, Ayesha; Sahin, Onur
    A new silver(I) 2D MOF (Ag -MOF) was synthesized from 3,4-pyridinedicarboxylic acid (PDCA) by sonication method and characterized by single crystal X-ray diffraction, elemental analysis and FTIR spectroscopy. The material was further utilized for DFT computation and electrochemical performance. Theoretical and practical results for Ag -MOF geometrical parameters were found to be in reasonable agreement. Small HOMO-LUMO energy distance of 0.47 eV confirmed that electron transfer was much feasible. Distribution of electron isodensities was elaborated by DFT and FMOs computation. Double redox peaks in CV voltammograms reflected the change in oxidation state. Multiple plateaus in GCD curves showed the pseudo-capacitive behavior. Ag -MOF exhibited 101 Cg -1 specific capacity (Q s ), 123 Wh.kg - 1 energy density and 12,960 W kg -1 power density at current density of 5 Ag -1 . There was a small difference in R ct and R i which revealed that Ag -MOF had great ability to store energy. Presence of semi-circular arc in the EIS spectrum directly dictates the supercapacitor behavior. The electrode showed 97.5 % cyclic stability after 5000 cycles.
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    Synergetic interplay of a nitrogen- and sulfur-rich copper bi-linker 2D cubic-layered MOF composite with MXene for improved hybrid supercapacitor application
    (Royal Soc Chemistry, 2025) Saeed, Maham; Sharif, Shahzad; Shah, Javed Hussain; Afzal, Tayyaba Tur Rehman; Shahbaz, Muhammad; Shehzad, Azhar Mehmood; Shahzad, Ayesha
    To combine the properties of batteries and capacitors in a single hybrid device, metal-organic frameworks have emerged as promising materials. In this study, by incorporation of a heteroatom (N, O and S)-based bi-linker, a novel copper-based two-dimensional metal-organic framework (Cu-SIP-MOF), derived from 5-sulfoisophathalic acid monosodium salt (SIP sodium salt) and 4,4-bipyridine was synthesized and characterized using different techniques. The conductivity of the extended 2D MOF was attributed to pi-d orbital contribution, which was further enhanced by fabricating its composite with MXene. The synthesized MOFs and its composites were electrochemically evaluated using different electroanalytical techniques such as cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy via three-electrode assembly. The composites of Cu-SIP-MOF with MXene (CM-200) in a 1 : 2 ratio possessed the highest specific capacity of 683.69 C g-1, highlighting the potential for their practical implementation in asymmetric hybrid devices. The material demonstrated an energy density and a power density of 62 W h kg-1 and 2330.4 W kg-1, respectively. It also expressed 98.3% coulombic efficiency after 5000 galvanic charge-discharge cycles. The significant values of specific capacity, energy density and power density of CM-200 make it a promising electrode material for a futuristic hybrid device.
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    Synergistic interplay of 1D bimetal Co-Ni-MOF@rGO for hybrid energy storage device
    (Elsevier Science Sa, 2025) Saeed, Maham; Sharif, Shahzad; Razia, Eesha Tur; Shahzad, Ayesha; Raza, Muhammad Arshad; Arshad, Beenash; Afaq, Qarar
    As current era research ignites the focus towards finding better electrode material for renewable energy devices so, a cobalt and nickel-based bimetallic metal organic framework derived from 1,2,4,5-benzenetetracarboxylic acid was synthesized and characterized by Single crystal X-ray diffraction, Powder X-Ray diffraction, SEM, BET, elemental analysis, FTIR and TGA. Owing to pseudocapacitve properties of Co-Ni-MOF due to 1D pi-d conjugated layers, reduced graphene oxide (rGO) in different ratios was used to improve its conductivity and the fabricated composites were examined in three electrode system. Excess amount of rGO can overly occupy the MOF structure reducing redox active sites and electrochemical performance. CoNi@rGO2 appeared as the best optimized sample with highest specific capacity, specific capacitance of 567.40C/g and 1260.8 F/g at 1 A/g respectively. For the practical viability, it was integrated into a hybrid device which delivered specific capacity of 319.21C/g, an energy density of 64.29 Wh/kg, power density of 5346.21 W/kg and 98.3 % columbic efficiency after 7000 cycles. CoNi@rGO2//AC appeared as an exceptional hybrid energy device with practical and financial worth paving the way to develop similar materials for futuristic energy storage applications.
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    Tuning the electrochemical performance of a copper-based 2D rectangular layered metal organic framework by incorporating reduced graphene oxide and polyaniline
    (Royal Soc Chemistry, 2026) Riasat, Madiha; Shahbaz, Muhammad; Ullah, Ghulam; Mushtaq, Muhammad Waheed; Saeed, Maham; Shahzad, Sundas; Shahzad, Ayesha
    To meet the challenge of developing efficient energy storage devices, metal organic frameworks (MOFs) with intrinsic properties have emerged as promising candidates. The conductivity and stability of the extended 1D pi-d and pi-pi stacking in a 2D MOF can be further enhanced by fabricating its composite with conductive materials. Herein, a nitrogen-containing 2D Cu-PDA MOF was synthesized and mixed with conductive materials, such as reduced graphene oxide (rGO) and polyaniline (PANI), to enhance the electrical conductivity. After structural investigation, the electrochemical attributes of Cu-PDA and its composites (Cu-PDA@rGO and Cu-PDA@PANI) have been explored by utilizing different electroanalytical techniques like CV, GCD and EIS analyses. In a three-electrode assembly, Cu-PDA@rGO shows a specific capacity of 551.31 C g-1. Hence, for practical applications, a hybrid supercapacitor has been designed by fabricating Cu-PDA@rGO against activated carbon (AC), which reveals a specific capacity of 159.4 C g-1, a specific energy of 32.10 Wh kg-1 and a specific power of 180.17 W kg-1 while maintaining a coulombic efficiency of 99.4% even after 5000 GCD cycles. These excellent findings demonstrate that Cu-PDA@rGO is a potential candidate for future energy storage devices.