Department Of Chemistry

Permanent URI for this communityhttps://kr.cup.edu.in/handle/32116/33

Browse

Author: search.filters.author.Ahmed, ImtiazSubject: search.filters.subject.Nanorods

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Interfacial Engineering of CuCo2S4/g-C3N4Hybrid Nanorods for Efficient Oxygen Evolution Reaction
    (American Chemical Society, 2021-07-29T00:00:00) Biswas, Rathindranath; Thakur, Pooja; Kaur, Gagandeep; Som, Shubham; Saha, Monochura; Jhajhria, Vandna; Singh, Harjinder; Ahmed, Imtiaz; Banerjee, Biplab; Chopra, Deepak; Sen, Tapasi; Haldar, Krishna Kanta
    Altering the morphology of electrochemically active nanostructured materials could fundamentally influence their subsequent catalytic as well as oxygen evolution reaction (OER) performance. Enhanced OER activity for mixed-metal spinel-type sulfide (CuCo2S4) nanorods is generally done by blending the material that has high conductive supports together with those having a high surface volume ratio, for example, graphitic carbon nitrides (g-C3N4). Here, we report a noble-metal-free CuCo2S4 nanorod-based electrocatalyst appropriate for basic OER and neutral media, through a simple one-step thermal decomposition approach from its molecular precursors pyrrolidine dithiocarbamate-copper(II), Cu[PDTC]2, and pyrrolidine dithiocarbamate-cobalt(II), Co[PDTC]2 complexes. Transmission electron microscopy (TEM) images as well as X-ray diffraction (XRD) patterns suggest that as-synthesized CuCo2S4 nanorods are highly crystalline in nature and are connected on the g-C3N4 support. Attenuated total reflectance-Fourier-transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy studies affirm the successful formation of bonds that bridge (Co-N/S-C) at the interface of CuCo2S4 nanorods and g-C3N4. The kinetics of the reaction are expedited, as these bridging bonds function as an electron transport chain, empowering OER electrocatalytically under a low overpotential (242 mV) of a current density at 10 mA cm-2 under basic conditions, resulting in very high durability. Moreover, CuCo2S4/g-C3N4 composite nanorods exhibit a high catalytic activity of OER under a neutral medium at an overpotential of 406 mV and a current density of 10 mA cm-2. � 2021 American Chemical Society.