School Of Basic And Applied Sciences

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    BiFeO3/g-C3N4/f-CNF ternary nanocomposite as an efficient photocatalyst for methylene blue dye degradation under solar light irradiation
    (Elsevier Ltd, 2023-06-21T00:00:00) Deeksha; Kour, Pawanpreet; Ahmed, Imtiaz; Haldar, Krishna Kanta; Yadav, C.S.; Sharma, Surender Kumar; Yadav, Kamlesh
    The development of Perovskite oxide photocatalysts with superior dye degradation efficiency under solar light irradiation has gained attention in recent years, owing to their extraordinary flexibility, chemical composition, and tunability. Herein, we report the facile synthesis of a novel ternary composite composed of BiFeO3 (BFO) perovskite, g-C3N4, and functionalized carbon nanofibers (f-CNF), referred to as BFO/g-C3N4/f-CNF using a simple solution method as a photocatalyst to accelerate the degradation of methylene blue dye. Detailed structural and microstructural features confirm the formation of a ternary composite composed of BFO nanoparticles and f-CNFs mounted on g-C3N4 nanosheets. The photocatalytic activity of the sample for the degradation of methylene blue dye was studied in solar light using UV�visible spectroscopy. The BFO/g-C3N4/f-CNF ternary composite displays excellent photocatalytic activity with a degradation rate of 87 % after illumination for 120 min under solar light than BFO, g-C3N4, and binary composites BFO/g-C3N4 and BFO/f-CNF. The highest rate constant (k = 0.01675 min?1) for BFO/g-C3N4/f-CNF further confirms improved photocatalytic efficiency. The red shift in the UV�visible absorption spectrum of BFO/g-C3N4/f-CNF indicates a reduced band gap (1.9 eV) compared to that of pure BFO (2.28 eV) and g-C3N4 ( 2.72 eV). A decrease in the photoluminescence intensity of the ternary composite compared to that of BFO indicates the inhibition of photoexcited electron recombination which results in the availability of more charge carriers for the photocatalytic process. The enhanced efficiency of BFO/g-C3N4/f-CNF can be explained by the synergistic effect between BFO and g-C3N4 and the incorporation of f-CNF further promotes the migration rate of electrons from BFO to g-C3N4. � 2023 Elsevier B.V.
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    Tuning the Morphology of Lanthanum Cobaltite Using the Surfactant-Assisted Hydrothermal Approach for Enhancing Oxygen Evolution Catalysis
    (Springer Science and Business Media Deutschland GmbH, 2022-09-01T00:00:00) Deeksha; Kour, Pawanpreet; Ahmed, Imtiaz; Haldar, Krishna Kanta; Yadav, Kamlesh
    The high consumption rate of fossil fuels to meet the global energy demands attracts the progress of innovative energy storage and conversion systems. Among them, water electrolysis shows major concern because of its great potential to produce clean hydrogen energy. The dawdling dynamics of the oxygen evolution reaction (OER) that occurs on the anode results in the low energy efficiency of the process. Perovskite oxide with transition metal on the B site possesses a high intrinsic as well as extrinsic activity toward OER. However, the low specific surface area restricts their catalytic activity. Here, we report on the synthesis of lanthanum cobaltite (LaCoO3) nanoparticles and bundles of nanorods using glycine and PVP surfactants, respectively, via the hydrothermal method. Structural characterizations confirmed the pure phase synthesis of LaCoO3 perovskite nanomaterials and further their electrocatalytic performance is investigated in an alkaline medium (1 M KOH). The results show that randomly oriented bundles of nanorods (average length 515 nm, average diameter 65 nm) exhibit smaller overpotential (? = 420 mV) at j = 10 mA cm?2 and the Tafel slope (99 mV dec?1) compared with nanoparticles (? = 450 mV and Tafel slope ~ 110 mV dec?1). The dramatically improved OER activity and larger electrochemical surface area (ECSA) of nanorods as compared to nanoparticles are because of the interconnected porous architecture of nanorods. Our work not only highlights the surfactant-assisted hydrothermal approach to synthesize the nanorods but also introduces the effect of a change in morphology on electrochemical activity. � 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.