Yazar "Shahzad, Ayesha" seçeneğine göre listele

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    Öğe
    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.
  • [ X ]
    Öğe
    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.