Browsing by Author "Vij, Ankush"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Fabrication and improvement in the electrochemical performance of a 2D g-C3N4-based symmetric supercapacitor device
    (2025) Vij, Ankush
    This work evaluates the possibility of employing 2-dimensional graphitic carbon nitride (2D g-C3N4) to be uti lized in supercapacitor applications as an anode material. Compared to traditional carbon-based materials, g- C3N4 (CN) has various benefits, including higher energy-density and rate-capability. Therefore, we investigated the performance of a CN-based supercapacitor synthesized using an efficient and cost-effective thermal poly merization method. X-ray diffraction (XRD) data investigation indicated hexagonal symmetry composed with space group P-6 m2, indicating CN with no discernible presence of any other phases. The XRD pattern was utilised to calculate the average crystallite size, which was around 2.87 nm. In a three-electrode arrangement, electrochemical studies were performed on the CN electrode. The outcomes of this study revealed the specific capacitance (Cs) to be around 35.2 F/g at 5 mV/s when measured using cyclic voltammetry (CV) and was 39.9 F/ g at 1.0 A/g when calculated by galvanostatic charge-discharge (GCD). Finally, the construction of 2D CN based symmetric supercapacitor device was manifested and its electrochemical performance was investigated. Elec trochemical studies of the symmetric supercapacitor device demonstrated a highest cell specific capacitance (Ccell) of 149.1 F/g using GCD at 0.5 A/g. The symmetric supercapacitor device exhibited an extraordinary Ecell of 141.8 Wh/kg at a Pcell of 925 W/kg. Overall, this work thoroughly analyzed the electrochemical features of 2D CN and their symmetric supercapacitor devices, and offered insightful information on its prospective use in the energy storage field, which showed that 2D CN has better electrochemical performance than other similar materials
  • No Thumbnail Available
    Item
    Lattice Distortion Creates Enhancements in Photocatalytic and Electrocapacitive Performance of Sol–Gel-Derived Cu-Doped NiTiO3
    (2025) Vij, Ankush
    A remarkable 35% enhancement in the photocatalytic and electrocatalytic abil ities of an ilmenite nickel titanate (NiTiO3) material is reported. This boost in catalytic performance is achieved by simply creating a static distortion in the rhombohedral unit cell by replacing a small proportion of a small-size nonde generate Ni (69 pm) with a large-size degenerate Cu (73pm). The materials are synthesized by using a simple sol–gel method. The appropriate doping amount of Cu facilitates the better separation of intrinsic charge carrier pairs by inhibiting their recombination. The photocatalytic and electrochemical activities of durable materials in aqueous MB dye (10ppm) and KOH (1molar) electrolyte solutions are found to be directly associated with this improvement in inherent charge carrier transfer characteristics. The enhanced photodissociation of MB dye (42–56%) and specific capacitance (381–450 F g 1) in a KOH (1molar)electrolyte are in full accord with the investigations carried out using crystallographic and optoelectronic analysis, charging–discharging measurements, and electro chemical impedance (EIS) spectroscopy investigations. Same material with high textural surface areas or controllable particle morphologies might show a far better photo/electrocatalytic performance in a variety of practical applications.
  • No Thumbnail Available
    Item
    Probing structural and luminescence properties of Ce nanocrystals via XAS, PL, and TL studies
    (2025) Vij, Ankush
    MgO:Ce and MgO:CeLi nanocrystals have been prepared using the solution combustion method and investigated for structural, electronic structure, photoluminescence, and thermoluminescence properties. X-ray diffraction (XRD) analysis revealed the single-phase formation of MgO:Ce amd MgO:CeLi compounds up to 0.1 mol% of Ce doping. The formation of CeO 2 2+ phase has been observed at 2 mol% Ce doping in MgO. Low energy shift in the Mg K-edge X-ray absorption near edge structure (XANES) spectra conveys favorable tetrahedral site occupancy of Mg 3 ions in MgO:Ce nanocrystals. The enhanced intensity of the O K-edge XANES feature, in MgO:Ce samples, reveals a more, p-projected, unoccupied density of states and significant hybridization of Ce 4f and O 2p states. Ce L edge XANES spectra confirmed the coexistence of Ce 4+ and Ce 3+ ions in the samples. Photoluminescence (PL) experiments, conducted with UV LED excitation at 275 nm and 310 nm, showed emissions in two regions; a blue region centered at 430 nm and a red region at 670 nm in pure MgO. Additionally, distinct emission bands corresponding to Ce 5d-4f transitions were observed and the Li co-doping could enhance the PL intensity. Thermoluminescence (TL) studies of the samples were conducted after being exposed to the different doses (100 Gy, 500 Gy, 1 kGy) of gamma radiation. The deconvolution of TL peaks has confirmed the presence of multiple traps. Kinetic parameters of TL glow peaks revealed re-trapping and closely spaced traps within the forbidden band gap. The stability and linear behavior of TL peaks demonstrated the excellent dosimetry characteristics of prepared MgO: CeLi nano phosphors.