Publications by authors named "Ankush V Biradar"

Transforming CO to CO reverse water-gas shift (RWGS) reaction is widely regarded as a promising technique for improving the efficiency and economics of CO utilization processes. Moreover, it is also considered as a pathway towards e-fuels. Cu-oxide catalysts are widely explored for low-temperature RWGS reactions; nevertheless, they tend to deactivate significantly under applied reaction conditions due to the agglomeration of copper particles at elevated temperatures.

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Herein, we report the synthesis of two-dimensional chiral Zn Salen covalent organic frameworks (COFs) () via rapid microwave-promoted condensation of C-symmetric 1,3,5-tris[(5--butyl-3-formyl-4-hydroxyphenyl)ethynyl]benzene with (1,2)-1,2-diaminocyclohexane in excellent yields. The synthesized chiral Zn Salen COF () showed a 454 m g BET surface area with excellent crystallinity and thermal stability. Further, the post-synthetic metal exchange reaction was performed for chiral Zn Salen COFs () with Mn(OAc)·4HO to synthesize chiral Mn Salen COFs () and utilized as an effective heterogeneous catalyst for the enantioselective epoxidation of styrenes and chromenes to afford chiral epoxides up to 72% .

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Sustainable chemistry research prioritizes reducing atmospheric carbon dioxide, and one logical solution is to develop adsorbents suitable for carbon capture and utilization. In this work, a new family of three-dimensional (3D) flower-like Mn-promoted MgO was synthesized by the coprecipitation method and used as an adsorbent for CO capture and a catalyst for CO utilization. The scanning electron microscopy (SEM) analysis of the samples shows a 3D architecture composed of thin nanosheets.

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In this work, we have reported a noble metal free heterogeneous photocatalyst to carry out direct (het)arene C-H arylation and solvent-free CO capture single-electron transfer processes at room temperature and under pressure. The catalytic system comprises a cobalt(III) complex grafted over the silica coated magnetic support for the efficient recovery of the photocatalytic moiety without hampering its light-harvesting capability. The novel Earth-abundant cobalt(III) based photocatalyst possesses various fascinating properties such as high surface area to volume ratios, large pore volume, crystalline behaviour, high metal loading, excellent stability and reusability.

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In this study, a facile method for the synthesis of leach proof and earth-abundant non-noble Ni nanoparticles on N-doped carbon nanotubes is reported. The catalyst was synthesized by an impregnation-carbonization method, wherein a Ni-chitosan complex upon carbonization in a 5% H2/N2 atmosphere at 800 °C yielded Ni-containing N-doped CNTs. Chitosan served as a single source of carbon and nitrogen, and the nanotube growth was facilitated by the in situ formed Ni nanoparticles.

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The gram-scale synthesis of important flavoring ketones via alkylation of acetoacetic ester on substituted benzylic carbon followed by decarboxylation using a heterogeneous, commercial, solid acid catalyst is reported. The flavoring ketones were synthesized by the alkylation of acetoacetic ester, which proceeds through an S1-type reaction to generate an alkylated (β-ketoester) intermediate at the benzylic carbon, which is decarboxylated under the acidic condition. Among the solid acid catalysts used, Amberlyst-15 was found to be the best catalyst under the solvent-free condition.

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Herein, we report a simple route for the synthesis of phosphonate functionalized Brønsted solid acid carbon spheres as heterogeneous catalyst for the valorization of bio-derived α-pinene oxide. The Brønsted acidity was generated via two steps; hydrothermal carbonization of sugar to produce carbon microspheres followed by PCl treatment to form phosphonate functionalized carbon. The presence of phosphonate was confirmed by CP-MAS P and C NMR.

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Global warming challenges are fueling the demand to develop an efficient catalytic system for the reduction of CO , which would contribute significantly to the control of climate change. Herein, as-synthesized bismuthoxide-decorated graphene oxide (Bi O @GO) was used as an electro/thermal catalyst for CO reduction. Bi O @GO is found to be distributed uniformly, as confirmed by scanning electron and transmission electron microscopic analysis.

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Development of novel and greener methods for the selective oxidation of various organic compounds is a challenging task. Herein, a novel protocol for the selective oxidation of aromatic amines to nitroaromatics at room temperature is developed. The oxidation reaction was carried out using a mixture of formic acid and aqueous hydrogen peroxide, which resulted in the in situ formation of performic acid.

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One of the most vital supports to sustain human life on the planet earth is the agriculture system that has been constantly challenged in terms of yield. Crop losses due to insect pest attack even after excessive use of chemical pesticides, are major concerns for humanity and environment protection. By the virtue of unique properties possessed by micro and nano-structures, their implementation in Agri-biotechnology is largely anticipated.

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Core-shell nanoparticles (CSNs) are a class of nanostructured materials that have recently received increased attention owing to their interesting properties and broad range of applications in catalysis, biology, materials chemistry and sensors. By rationally tuning the cores as well as the shells of such materials, a range of core-shell nanoparticles can be produced with tailorable properties that can play important roles in various catalytic processes and offer sustainable solutions to current energy problems. Various synthetic methods for preparing different classes of CSNs, including the Stöber method, solvothermal method, one-pot synthetic method involving surfactants, etc.

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We report calcium phosphate (CaP) nanocapsule crowned multiwalled carbon nanotubes (CNT-GSH-G4-CaP) as a novel platform for intracellular delivery of an anticancer drug. As a proof-of-concept, CNT-GSH-G4-CaP demonstrates release of anticancer drug doxorubicin hydrochloride (DOX) within intracellular lysosomes from the interior cavity of CNT upon pH triggered CaP dissolution. Importantly, we found that the CNT with a CaP nanolid can efficiently prevent untimely drug release at physiological pH but promotes DOX release at increased acidic milieu as observed in subcellular compartments such as lysosomes (∼5.

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Recombinant expression of Capsicum annuum proteinase inhibitors (CanPI-13) and its application via synthetic carrier for the crop protection is the prime objective of our study. Herein, we explored proteinase inhibitor peptide immobilization on silica based nanospheres and rods followed by its pH mediated release in vitro and in vivo. Initial studies suggested silica nanospheres to be a suitable candidate for peptide immobilization.

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We report the synthesis of a trifunctional catalyst containing amine, sulphonic acid and Pd nanoparticle catalytic groups anchored on the pore walls of SBA-15. The catalyst efficiently catalyzes one-pot three-step cascade reactions comprising deacetylation, Henry reaction and hydrogenation, giving up to ∼100% conversion and 92% selectivity to the final product.

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In vivo and in vitro systems were employed to investigate the biocompatibility of two forms of calcined mesoporous silica microparticles, MCM41-cal and SBA15-cal, with ventricular myocytes. These particles have potential clinical use in delivering bioactive compounds to the heart. Ventricular myocytes were isolated from 6 to 8 week male Wistar rats.

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Background: The biocompatibility of two forms of calcined mesoporous silica particles, labeled as MCM41-cal and SBA15-cal, with fetal blood mononuclear cells was assessed in vitro.

Methods And Results: Fetal mononuclear cells were isolated from umbilical cord blood and exposed to 0.5 mg/mL of MCM41-cal or SBA15-cal for several hours.

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Current interest in natural photosynthesis as a blueprint for solar energy conversion has led to the development of a biohybrid photovoltaic cell in which bacterial photosynthetic membrane vesicles (chromatophores) have been adsorbed to a gold electrode surface in conjunction with biological electrolytes (quinone [Q] and cytochrome c; Magis et al. [2010] Biochim. Biophys.

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A new layered MOF material [Co(Hoba)(2)·2H(2)O] (1) (H(2)oba = 4,4'-oxybis(benzoic acid)) has been synthesized and used as a highly recyclable heterogeneous catalyst for olefin epoxidation reactions. Both high conversion (96%) and high selectivity of epoxide products (96%) are achieved.

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We report the synthesis and catalytic activities of highly stable, hollow nanoreactors, called SiO(2)/Pd/h-ZrO(2), which consist of silica microsphere (SiO(2))-supported Pd nanoparticle multicores (Pd) that are encapsulated with a hollow and nanoporous ZrO(2) shell (h-ZrO(2)). The SiO(2)/Pd/h-ZrO(2) nanoreactors are fabricated by first synthesizing SiO(2)/Pd/SiO(2)/ZrO(2) microspheres, and then etching the inner SiO(2) shell with dilute NaOH solution. The hollow and nanoporous ZrO(2) shell of the nanoreactors serves two important functions: 1) it provides reactants direct access to the Pd nanoparticle multicores inside the SiO(2)/Pd/h-ZrO(2) nanoreactors during catalysis, and 2) it stabilizes the Pd nanoparticles or protects them from aggregation/sintering.

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We report the synthesis, characterization, and catalytic properties of novel monodisperse SiO(2)@Pd-PAMAM core-shell microspheres containing SiO(2) microsphere cores and PAMAM dendrimer-encapsulated Pd nanoparticle (Pd-PAMAM) shells. First, SiO(2) microspheres, which were prepared by the Stöber method, were functionalized with vinyl groups by grafting their surfaces with vinyltriethoxysilane (VTS). The vinyl groups were then converted into epoxides by using m-chloroperoxybenzoic acid.

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We report on the pneumatocyte structure and function of mouse lung specimens exposed in vitro to two calcined mesoporous silica particles, MCM41-cal (spheres, ∼300 to 1000 nm in diameter) and SBA15-cal (irregular rods averaging ∼500 nm in diameter and ∼1000 nm in length). These mesoporous silica particles are in consideration for potential medical application as delivery vehicles for genes, drugs, and bio-imagers. In the study, lung specimens (about 10 mg each) were excised from male Balb/c mice, immediately immersed in Krebs-Henseleit buffer, ice-cold, and continuously gassed with O(2):CO(2) (95:5).

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A novel in vitro system was developed to investigate the effects of two forms of calcined mesoporous silica particles (MCM41-cal and SBA15-cal) on cellular respiration of mouse tissues. O(2) consumption by lung, liver, kidney, spleen, and pancreatic tissues was unaffected by exposure to 200 μg/mL MCM41-cal or SBA15-cal for several hours. Normal tissue histology was confirmed by light microscopy.

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We report a solution-phase synthetic route to copper nanoparticles with controllable size and shape. The synthesis of the nanoparticles is achieved by the reduction of copper(II) salt in aqueous solution with hydrazine under air atmosphere in the presence of poly(acrylic acid) (PAA) as capping agent. The results suggest that the pH plays a key role for the formation of pure copper nanoparticles, whereas the concentration of PAA is important for controlling the size and geometric shape of the nanoparticles.

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We report a new and simple one-pot synthetic method to produce mesoporous silica and nanoporous solid acid catalyst capable of catalyzing pinacole-pinacolone rearrangement and esterification reactions, by preparing a solvent washable phosphonated triblock copolymer template and self-assembling it in the presence of alkoxysilane.

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A facile method for the synthesis of porous platinum nanoparticles by transmetallation reactions between sacrificial nickel nanoparticles and chloroplatinic acid (H(2)PtCl(6)) in solution, as well as at the constrained environment of the air-water interface, using a Langmuir-Blodgett instrumental setup is presented. To carry out the transmetallation at the air-water interface hydrophobized nickel nanoparticles are assembled as a monolayer on the sub phase containing platinum ions. The porous Pt nanoparticles obtained as a result of the reaction are found to act as extremely good catalysts for hydrogenation reaction.

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