Journal Articles

Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884

Browse

Author: search.filters.author.Hegde, A.P.Subject: search.filters.subject.Potassium hydroxide

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Enhancing conductivity of Bi2O3 through ‘Fe3+’ doping for pseudocapacitor application
    (Springer Science and Business Media Deutschland GmbH, 2025) G, L.S.; Bhat, K.S.; Mukesh, P.; Hegde, A.P.; Kumar, A.; Brijesh, K.; Nagaraja, H.S.
    Binary metal oxides have emerged as pSromising materials for advanced electrochemical energy storage systems due to their superior performance characteristics. In this study, we focus on bismuth oxide (Bi?O?), a material renowned for its high theoretical capacity, wide potential range, and exceptional power density, as a potential candidate for supercapacitors. Iron doping was employed as a strategy to enhance its electrochemical performance and modulate the band gap, thereby improving conductivity and charge storage efficiency. Fe-doped bismuth oxide (Fe-Bi?O?) was synthesized via a solvothermal method with varying iron concentrations (2%, 4%, and 6%), followed by annealing. The pure and iron-doped bismuth oxide samples revealed a combination of monoclinic and cubic phases and a prominent micro-sheet architecture. The introduction of iron doping led to a noticeable reduction in the band gap, highlighting its role in fine-tuning the electronic properties for enhanced energy storage capabilities. The electrochemical evaluation highlighted the 4% Fe-Bi?O? sample as the optimal composition, achieving a remarkable specific capacity of 904 F g?1, a substantial improvement over 101 F g?1 for pristine Bi?O?, at 1 A g?1 in a 2 M KOH electrolyte. Moreover, this sample exhibited outstanding cyclic stability, retaining 104 F g?1 after 2000 cycles at 10 A g?1. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.
  • No Thumbnail Available
    Item
    Ag2Cu2O3 Nanorods as Electrocatalysts for Hydrogen Production and Overall Water Splitting
    (American Chemical Society, 2025) Kumar, A.; Hegde, A.P.; Puttur, M.; Gangadharappa, L.S.; Hosakoppa, N.S.
    In this research, a series of Ag2Cu2O3 nanorods as electrocatalysts were prepared with three different drying temperatures (namely, W - 50, W - 80, and W - 120), utilizing a regular coprecipitation approach. These nanorods’ surface morphology and structural attributes were thoroughly characterized using Field Emission Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy, while X-ray diffraction provided insight into their crystal structures. The compositional analysis was accomplished via X-ray photoelectron spectroscopy and Raman spectroscopy. The W - 50 catalyst exhibited the most promising electrochemical response among the synthesized samples. In the solution of 1 M KOH, at a current density of 10 mA cm-2, it demonstrated modest overpotential values and Tafel slopes of 81 and 97 mV dec-1 for the hydrogen evolution reaction (HER), whereas 409 and 140 mV dec-1 for the oxygen evolution reaction (OER). When tested with a two-electrode electrolyzer, W - 50 serving as together the anode and cathode, a trivial cell voltage of 1.9842 V was required to accomplish a current density of 100 mA cm-2, with surprising stability over 50 h of continuous operation at 200 mA cm-2 for overall water splitting. Additionally, W - 50 displayed excellent performance for HER; it necessitated an overpotential of 337 mV to accomplish an extreme current density of 800 mA cm-2. This inquiry provides precious perceptions into the importance of confined spaces within transition metal oxide-based catalysts, advancing their application in electrocatalysis. © 2025 American Chemical Society.
  • No Thumbnail Available
    Item
    Melamine – Ni-MIL-88A blend derived Trevorite/C-g-C3N4 for stable and efficient overall electrocatalytic water splitting applications
    (Elsevier Ltd, 2025) Hegde, A.P.; P, M.; G, L.; Kumar, A.; Nagaraja, H.S.
    The electrocatalytic splitting of water into hydrogen and oxygen plays a pivotal role in addressing the energy demands associated with expanding anthropogenic activities. The design of economically feasible and effective electrocatalytic materials for water electrolysis is imperative for the sustainable production of hydrogen and oxygen. In this context, this study introduces an electrocatalyst design comprising graphitic carbon nitride (g-C3N4) and Trevorite (Ni(Ni, Fe)2O4) synthesized through the pyrolysis of a mixture Ni-substituted metal–organic framework (MOF) MIL-88A and of melamine. The synthesized material was evaluated as an electrocatalyst for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). The nickel foam coated with this electrocatalyst exhibits a performance characterized by lower overpotentials of 121 mV for HER and 231 mV for OER at a current density of 10 mA cm-2 in an alkaline medium of 1 M KOH. Furthermore, the composite demonstrated an excellent overall water splitting capacity, maintaining a high current density of 500 mA cm-2 for more than 50 h of continuous electrolysis in 1 M KOH solution with a minimal voltage increase of approximately 0.025 V. © 2025