Browsing by Subject "Nanocatalyst"

Now showing 1 - 3 of 3

Open Access
Biocompatible supramolecular catalytic one-dimensional nanofibers for efficient labeling of live cells
(American Chemical Society, 2015) Khalily, M. A.; Gulseren, G.; Tekinay, A. B.; Güler, Mustafa O.
Understanding complex cellular functions requires study and tracking of biomolecules such as proteins, glycans, and lipids in their natural environment. Herein, we report the first supramolecular nanocatalyst for bioorthogonal click reaction to label live cells. This biocompatible and biodegradable nanocatalyst was formed by self-assembled peptide nanofibers complexed with copper ions. The supramolecular nanocatalyst enhanced azide-alkyne cycloaddition reaction rate under physiological conditions and was shown to be useful for efficient bioorthogonal labeling of live cells.
Open Access
Facile synthesis of bimetallic nanoparticles with diverse nanostructures using metal acetylacetonates
(2024-01) Sayma, Dalya M. F.
Bimetallic nanoparticles (NPs) have become a fundamental subject in the field of nanoscience and inorganic chemistry. Owing to the fascinating optical and catalytic properties that rise from their synergetic effect, plasmonic-catalytic bimetallic NPs, in particular, are employed in a myriad of applications such as catalysis, sensing and photocatalysis. Optical properties of plasmonic NPs such as gold or silver NPs are based on the localized surface plasmon resonance (LSPR) in the visible spectral range. Plasmonic NPs enhance the localization of electromagnetic fields, converting light to hot carriers or heat that can be used to drive chemical reactions. On the other hand, catalytic metals, which have d-bands close to the Fermi-level, make strong binding to reactants and lower the activation energy of chemical reactions. The properties of plasmonic-catalytic bimetallic NPs such as efficiency or product selectivity in the chemical reaction do not only rely on factors like size and composition of metal NPs, but more importantly, on the types of nanostructures formed. Herein, several nanostructures were synthesized by developing a facile approach using metal acetylacetonates. The synthesized NPs include bare silver NPs, bare palladium NPs, Pd@Ag core-shell NPs, Pd@Ag nanowires, Ag-Pd alloyed core-satellite NPs, Ag-Pt alloyed nano-stars and concave nano-cubes, and trimetallic AgPdPt NPs. In this study, it was found that the temperature, composition of metal components, and amount of capping and reducing agents play a key role in the synthesis of different types of bimetallic NPs. This study is important in the field of nanochemistry as it provides a novel synthesis method for generating plasmonic-catalytic bimetallic NPs.
Open Access
Nickel nanoparticles decorated on electrospun polycaprolactone/chitosan nanofibers as flexible, highly active and reusable nanocatalyst in the reduction of nitrophenols under mild conditions
(Elsevier, 2017-04) Karakas, K.; Celebioglu A.; Celebi, M.; Uyar, Tamer; Zahmakiran, M.
Today, the reduction of nitro aromatics stands a major challenge because of the pollutant and detrimental nature of these compounds. In the present study, we show that nickel(0) nanoparticles (Ni-NP) decorated on electrospun polymeric (polycaprolactone(PCL)/chitosan) nanofibers (Ni-NP/ENF) effectively catalyze the reduction of various nitrophenols (2-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol) under mild conditions. Ni-NP/ENF nanocatalyst was reproducibly prepared by deposition-reduction technique. The detailed characterization of these Ni-NP/ENF based nanocatalyst have been performed by using various spectroscopic tools including ICP-OES, P-XRD, XPS, SEM, BFTEM, HRTEM and BFTEM-EDX techniques. The results revealed the formation of well-dispersed nickel(0) NP (dmean = 2.71–2.93 nm) on the surface of electrospun polymeric nanofibers. The catalytic activity of the resulting Ni-NP/ENF was evaluated in the catalytic reduction of nitrophenols in aqueous solution in the presence of sodium borohydride (NaBH4) as reducing agent, in which Ni-NP/ENF nanocatalyst has shown high activity (TOF = 46.2 mol 2-nitrophenol/mol Ni min; 48.2 mol 2,4-dinitrophenol/mol Ni min; 65.6 mol 2,4,6-trinitrophenol/mol Ni min). More importantly, due to the nanofibrous polymeric support, Ni-NP/ENF has shown a flexible characteristics along with reusability property. Testing the catalytic stability of Ni-NP/ENF revealed that this new catalytic material provides high reusability performance (at 3rd reuse 86% for 2-nitrophenol, 83% 2,4-dinitrophenol and 82% 2,4,6-trinitrophenol) for the reduction of nitrophenols even at room temperature and under air. The present study reported here also includes the compilation of wealthy kinetic data for Ni-NP/ENF catalyzed the reduction of nitrophenols in aqueous sodium borohydride solution depending on temperature and type of support material (Al2O3, C, SiO2) to understand the effect of the support material and determine the activation parameters.