Journal ArticleDOI
Synthesis of Tetrahexahedral Platinum Nanocrystals with High-Index Facets and High Electro-Oxidation Activity
TLDR
Platinum NCs of unusual tetrahexahedral (THH) shape were prepared at high yield by an electrochemical treatment of Pt nanospheres supported on glassy carbon by a square-wave potential to exhibit much enhanced catalytic activity for equivalent Pt surface areas for electro-oxidation of small organic fuels such as formic acid and ethanol.Abstract:
The shapes of noble metal nanocrystals (NCs) are usually defined by polyhedra that are enclosed by {111} and {100} facets, such as cubes, tetrahedra, and octahedra. Platinum NCs of unusual tetrahexahedral (THH) shape were prepared at high yield by an electrochemical treatment of Pt nanospheres supported on glassy carbon by a square-wave potential. The single-crystal THH NC is enclosed by 24 high-index facets such as {730}, {210}, and/or {520} surfaces that have a large density of atomic steps and dangling bonds. These high-energy surfaces are stable thermally (to 800°C) and chemically and exhibit much enhanced (up to 400%) catalytic activity for equivalent Pt surface areas for electro-oxidation of small organic fuels such as formic acid and ethanol.read more
Citations
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Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?
TL;DR: A comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals, including a brief introduction to nucleation and growth within the context of metal Nanocrystal synthesis, followed by a discussion of the possible shapes that aMetal nanocrystal might take under different conditions.
Journal ArticleDOI
Anatase TiO(2) single crystals with a large percentage of reactive facets
Hua Gui Yang,Chenghua Sun,Shi-Zhang Qiao,Jin Zou,Gang Liu,Sean C. Smith,Hui-Ming Cheng,Gao Qing Lu +7 more
TL;DR: This work synthesized uniform anatase TiO2 single crystals with a high percentage (47 per cent) of {001} facets using hydrofluoric acid as a morphology controlling agent and demonstrates that for fluorine-terminated surfaces this relative stability is reversed.
Journal ArticleDOI
Pd-Pt Bimetallic Nanodendrites with High Activity for Oxygen Reduction
Byungkwon Lim,Majiong Jiang,Pedro H. C. Camargo,Eun Chul Cho,Jing Tao,Xianmao Lu,Yimei Zhu,Younan Xia +7 more
TL;DR: Pd-Pt bimetallic nanodendrites consisting of a dense array of Pt branches on a Pd core by reducing K2PtCl4 with L-ascorbic acid in the presence of uniform Pd nanocrystal seeds in an aqueous solution showed relatively large surface areas and particularly active facets toward the oxygen reduction reaction (ORR), the rate-determining step in a proton-exchange membrane fuel cell.
Journal ArticleDOI
Shape Control of Colloidal Metal Nanocrystals
TL;DR: In this paper, an overall picture of shaped metal particles is presented, with a particular focus on solution-based syntheses for the noble metals, emphasizing key factors that result in anisotropic, nonspherical growth such as crystallographically selective adsorbates and seeding processes.
Journal ArticleDOI
Nanostructured Materials for Electrochemical Energy Conversion and Storage Devices
TL;DR: In this article, the authors describe some recent developments in nanostructured anode and cathode materials for lithium-ion batteries, addressing the benefits of nanometer-size effects, the disadvantages of 'nano', and strategies to solve these issues such as nano/micro hierarchical structures and surface coatings, as well as developments in the discovery of nano-structured Pt-based electrocatalysts for direct methanol fuel cells (DMFCs).
References
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Journal ArticleDOI
Shape-Controlled Synthesis of Gold and Silver Nanoparticles
Yugang Sun,Younan Xia +1 more
TL;DR: Monodisperse samples of silver nanocubes were synthesized in large quantities by reducing silver nitrate with ethylene glycol in the presence of poly(vinyl pyrrolidone) (PVP), characterized by a slightly truncated shape bounded by {100, {110}, and {111} facets.
Journal ArticleDOI
Improved Oxygen Reduction Activity on Pt3Ni(111) via Increased Surface Site Availability
Vojislav R. Stamenkovic,Vojislav R. Stamenkovic,Ben Fowler,Bongjin Simon Mun,Guofeng Wang,Philip N. Ross,Chris Lucas,Nenad M. Markovic +7 more
TL;DR: It is demonstrated that the Pt3Ni( 111) surface is 10-fold more active for the ORR than the corresponding Pt(111) surface and 90-foldMore active than the current state-of-the-art Pt/C catalysts for PEMFC.
Journal ArticleDOI
Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles
TL;DR: Tetrahedral, cubic, irregular-prismatic, icosahedral, and cubo-octahedral particle shapes were observed, whose distribution was dependent on the concentration ratio of the capping polymer material to the platinum cation.
Journal ArticleDOI
Stabilization of Platinum Oxygen-Reduction Electrocatalysts Using Gold Clusters
TL;DR: It is demonstrated that platinum (Pt) oxygen-reduction fuel-cell electrocatalysts can be stabilized against dissolution under potential cycling regimes by modifying Pt nanoparticles with gold (Au) clusters, and data suggest that the Au clusters confer stability by raising the Pt oxidation potential.
Journal ArticleDOI
Hydrogen Sensors and Switches from Electrodeposited Palladium Mesowire Arrays
TL;DR: Hydrogen sensors and hydrogen-activated switches were fabricated from arrays of mesoscopic palladium wires fabricated by electrodeposition onto graphite surfaces and transferred onto a cyanoacrylate film.