Surface structures of shape-controlled Pt nanoparticles have been estimated using cyclic voltammetry (CV) and infrared reflection absorption spectroscopy (IRAS). Cubic and cuboctahedral Pt nanoparticles are prepared using a capping polymer. These nanoparticles give CVs similar to those of single crystal electrodes of Pt in sulfuric acid solution. The CV of cubic nanoparticles is similar to that of the Pt(510) [=5(100)-(110)] electrode, while the CV of cuboctahedral nanoparticles is reproduced well with the convolution of Pt(766) [=13(111)-(100)] and Pt(17 1 1) [=9(100)-(111)] electrodes. These results suggest that the planes of the cubic and cuboctahedral nanoparticles are composed of step-terrace and atomically flat terraces, respectively. Adsorbed carbon monoxide (CO) on the shape-controlled nanoparticles gives the IR bands that are assigned to on-top and bridged CO. The band of on-top CO is deconvoluted to two bands: the higher and the lower frequency bands are assigned to the CO on the plane and the edges of the nanoparticles, respectively. On-top CO adsorbed on the edges is oxidized at more negative potential than that on the planes. Edge sites of the nanoparticles promote CO oxidation.
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http://dx.doi.org/10.1002/cphc.200900486 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, USA, 16802.
Ethylene glycol or one of its oxidation products are believed to serve as reducing agents in the shape-controlled synthesis of Ag nanocubes (NCs) by the polyol process. The identity of end-groups of polyvinylpyrrolidone (PVP) impacts shape control with alcohol and aldehyde moieties serving as a primary Ag reducing agent. We explored the role of PVP end-groups in the polyol process by measuring the dependence of particle number density of Ag NCs produced on the initial concentration(s) of Ag and PVP using small angle x-ray scattering and statistically large particle size distributions analyzed by scanning electron microscopy.
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October 2024
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
J Oleo Sci
September 2024
Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science.
Shape-controlled nanocrystals, such as nanoflowers, are expected to serve as innovative nanocatalysts with high catalytic activity. It is well-established that these nanocrystals can be readily synthesized with specific shapes using colloidal methods in solutions containing capping agents. However, these capping agents tend to reduce the catalytic activity of nanocatalysts.
View Article and Find Full Text PDFCurr Pharm Des
October 2024
School of Pharmacy, Graphic Era Hill University, Dehradun, India.
Drug delivery systems rely heavily on nanoparticles because they provide a targeted and monitored release of pharmaceuticals that maximize therapeutic efficacy and minimize side effects. To maximize drug internalization, this review focuses on comprehending the interactions between biological systems and nanoparticles. The way that nanoparticles behave during cellular uptake, distribution, and retention in the body is determined by their shape.
View Article and Find Full Text PDFEnviron Res
October 2024
Laboratory of Advanced Materials and Interfaces (LIMA), University of Monastir, Faculty of Science of Monastir, Avenue of Environment, 5000, Monastir, Tunisia.
This study presents a novel blend of synthesis techniques for shape-controlled ZnS nanoparticles. Zinc sulfide (ZnS) nanoparticles with distinct morphologies cauliflower-like microstructures (∼4.5 μm) and uniform nanospheres (200-700 nm) were synthesized through an innovative blend of precipitation and hydrothermal techniques.
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