Department Of Chemistry

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Author: search.filters.author.Biswas, RathindranathSubject: search.filters.subject.Nanorods

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    Porous nanorods by stacked NiO nanoparticulate exhibiting corn-like structure for sustainable environmental and energy applications
    (Royal Society of Chemistry, 2023-07-20T00:00:00) Manjunath, Vishesh; Bimli, Santosh; Singh, Diwakar; Biswas, Rathindranath; Didwal, Pravin N.; Haldar, Krishna Kanta; Deshpande, Nishad G.; Bhobe, Preeti A.; Devan, Rupesh S.
    A porous 1D nanostructure provides much shorter electron transport pathways, thereby helping to improve the life cycle of the device and overcome poor ionic and electronic conductivity, interfacial impedance between electrode-electrolyte interface, and low volumetric energy density. In view of this, we report on the feasibility of 1D porous NiO nanorods comprising interlocked NiO nanoparticles as an active electrode for capturing greenhouse CO2, effective supercapacitors, and efficient electrocatalytic water-splitting applications. The nanorods with a size less than 100 nm were formed by stacking cubic crystalline NiO nanoparticles with dimensions less than 10 nm, providing the necessary porosity. The existence of Ni2+ and its octahedral coordination with O2? is corroborated by XPS and EXAFS. The SAXS profile and BET analysis showed 84.731 m2 g?1 surface area for the porous NiO nanorods. The NiO nanorods provided significant surface-area and the active-surface-sites thus yielded a CO2 uptake of 63 mmol g?1 at 273 K via physisorption, a specific-capacitance (CS) of 368 F g?1, along with a retention of 76.84% after 2500 cycles, and worthy electrocatalytic water splitting with an overpotential of 345 and 441 mV for HER and OER activities, respectively. Therefore, the porous 1D NiO as an active electrode shows multifunctionality toward sustainable environmental and energy applications. � 2023 The Royal Society of Chemistry.
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    Interfacial design of gold/silver core-shell nanostars for plasmon-enhanced photocatalytic coupling of 4-aminothiophenol
    (Royal Society of Chemistry, 2021-10-02T00:00:00) Kaur, Gagandeep; Tanwar, Swati; Kaur, Vishaldeep; Biswas, Rathindranath; Saini, Sangeeta; Haldar, Krishna Kanta; Sen, Tapasi
    Chemical reactions under mild conditions mediated by localized surface plasmon resonance (LSPR) of metals have emerged as a functional research field. In the present study, we report an interfacial designing procedure for the fabrication of a class of bimetallic hybrid nanomaterials as a profoundly active photocatalyst for the conversion of para-aminothiophenol (PATP) into 4,4?-dimercaptoazobenzene. For this purpose, core-shell nanostars composed of gold (core) and silver (shell) (Au/Ag NSs) were utilized as both surface-enhanced Raman scattering substrate and plasmon driven catalyst under 532 nm laser excitation. Au/Ag NSs with sharp tips display excellent surface-enhanced Raman scattering (SERS) efficiency of PATP. Employing the SERS study, it has been found that PATP rapidly converts into its dimerized product DMAB within few seconds by surface photochemical reaction in the Au-Ag heterojunction of core-shell nanostars. Au/Ag NSs with multiple sharp tips exhibit intense LSPR and highly strong electric fields are created at the tips, which enables the generation of hot electrons responsible for the rapid conversion reaction. Such well-designed interfacial bimetallic nanostars could have potential applications in surface enhanced spectroscopy, biosensing, and photoinduced surface catalysis. This journal is � The Royal Society of Chemistry.
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    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.
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    One pot synthesis of Au embedded ZnO nanorods composite heterostructures with excellent photocatalytic properties
    (Central University of Punjab, 2018) Biswas, Rathindranath; Haldar, Krishna Kanta
    Here, we have designed a noble composite nanostructure by embedding Au nanoparticles into ZnO nanorods surface in one pot synthesis as a photocatalyst. The formation the composite nanostructure was confirmed by X-ray diffraction, Xray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) investigations. Microscopic studies suggest that spherical Au nanoparticles are nucleated on the ZnO nanorods surface. XPS shows shifting of peak positions towards higher binding energy indicating charge transfer from ZnO to Au in the composite nanostructures. This is unambiguously confirmed by the steady state spectroscopic studies. It is found that 95.7% of Methylene blue (MB) dye is degraded by the composite nanostructure after 140 min under UV light illumination, and the apparent rate constant is found to be 0.013 min-1 . This new class of Au nanoparticles embedded ZnO nanorods composite nanostructure opens up new possibilities in photocatalytic, solar energy conversion, photovoltaic, and other new emerging applications.