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Pt nanoparticles, nanowire and nanopores structures

[size=5][b][color=Red]Pt nanoparticles, nanowire and nanopores structures sytheisis and characterization[/color][/b][/size]
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:hot1 最近对这个问题有些兴趣，想收集一下这方面的专题，欢迎大家分享和支持。可以只提供文献基本讯息（题目，作者，杂志卷期页码，年限和摘要等）
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提供基本讯息者奖励3-5金币，提供自己的观点者（包括推荐制备方法，特点和表征，含电化学，微结构等）亦奖励2-10金币。综述文献3-8金币。提供:box下载另外奖励6-20金币。dr/Lw R3c8i U`+P

is^0H9G 拿金币的好机会，欢迎参加。$vt1szV%H}
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[size=5][b]Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles [/b][/size]:hot1
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TS Ahmadi, ZL Wang, TC Green, A Henglein, MA El-Sayed)kVm&k'M1a?
T. S. Ahmadi, T. C. Green, M. A. El-Sayed, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA. Z. L. Wang, School of Material Sciences and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA. A. Henglein, Hahn-Meitner Institut, Abteilung Kleinteilchenforschung, 14109 Berlin, Germany.3Ls5V3GNJgA

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/qo+H\'v2KqJ The shapes and sizes of platinum nanoparticles were controlled by changes in the ratio of the concentration of the capping polymer material to the concentration of the platinum cations used in the reductive synthesis of colloidal particles in solution at room temperature. 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. Controlling the shape of platinum nanoparticles is potentially important in the field of catalysis.
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[[i] 本帖最后由 nanosurface 于 2007-09-05 10:55 编辑 [/i]]

[size=5][b]Synthesis of Tetrahexahedral Platinum Nanocrystals with High-Index Facets and High Electro-Oxidation Activity.[/b][/size]
YD6JI~{7z&rAD     N. Tian, Z.-Y. Zhou, S.-G. Sun, Y. Ding, and Z. L. Wang (2007)
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G(l%c0P&I.O[     [b]Science [/b]316, 732-735 （2007）； DOI: 10.1126/science.1140484V_5F:x
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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.

[b][size=5]Catalysis with transition metal nanoparticles in colloidal solution: Nanoparticle shape dependence and stability[/size][/b]:hot1
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g ~9Gx/wc/G*c!e6H [b][i]JOURNAL OF PHYSICAL CHEMISTRY [/i][/b][b]B 109[/b] (26): 12663-12676 JUL 7 2005
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While the nanocatalysis field has undergone an explosive growth during the past decade, there have been very few studies in the area of shape-dependent catalysis and the effect of the catalytic process on the shape and size of transition metal nanoparticles as well as their recycling potential. Metal nanoparticles of different shapes have different crystallographic facets and have different fraction of surface atoms on their corners and edges, which makes it interesting to study the effect of metal nanoparticle shape on the catalytic activity of various organic and inorganic reactions. Transition metal nanoparticles are attractive to use as catalysts due to their high surface-to-volume ratio compared to bulk catalytic materials, but their surface atoms could be so active that changes in the size and shape of the nanoparticles could occur during the course of their catalytic function, which could also affect their recycling potential. In this Feature Article, we review our work on the effect of the shape of the colloidal nanocatalyst on the catalytic activity as well as the effect of the catalytic process on the shape and size of the colloidal transition metal nanocatalysts and their recycling potential. These studies provide important clues on the mechanism of the reactions we studied and also can be very useful in the process of designing better catalysts in the future.

[size=5][b]Shape-controlled synthesis of Pt nanocrystals: an evolution of the tetrahedral shape[/b][/size]pzqzDA0Z"K

6Q4`MZR#}9p/G6Y Yu YT (Yu, Ying-Tao), Xu BQ (Xu, Bo-Qing)?H5^E\

$R7b mod~.pP [b][i]APPLIED ORGANOMETALLIC CHEMISTRY [/i][/b][b]20 [/b](10): 638-647 OCT 2006 wfH Ub;O:FA
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Platinum nanocrystals with sizes smaller than 10 nm are obtained by H-2-reduction of aqueous K2PtCl6 in the presence of different concentrations of poly (N-vinyl-2-pyrrolidone; PVP: M-w approximate to 360 000) at pH = 2.5-7.0. Tetrahedral Pt nanocrystals (3-10 nm) are produced with high selectivity (73-83% by number) at moderate PVP:K2PtCl6 ratios. The co-existing round/spheroidal crystallites are found to be smaller than the tetrahedrally shaped ones in the systems of varying K2PtCl6:PVP ratios. Careful examinations of the particle size and shape evolution of the crystallites at different stages of the crystal growth with transmission electron microscopy (TEM) and ultraviolet-visible absorption spectroscopy (UV-vis) suggest that the tetradedrally shaped Pt crystallites share the same type of nuclei with the round ones at the early stage of the crystal formation. Evolution of the tetrahedral shape happens in the later slow crystal growth.

[b][size=5]"Green synthesis" of monodisperse Pt nanoparticles and their catalytic properties[/size][/b]
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Pm,L Yang W (Yang, Wen), Ma Y (Ma, Ying), Tang J (Tang, Jiang), Yang XR (Yang, Xiurong)
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.\r:vz$q%p gw k [b][i]COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS[/i][/b] [b]302[/b] (1-3): 628-633 JUL 20 2007
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5U(Y:Y;ky1d A green synthetic strategy to prepare monodisperse Pt nanoparticles was reported. Aminodextran acted as the reductive and protective agents, and Pt nanoparticles were characterized by UV/vis spectroscopy (UV-vis), Pt nanoparticles were conveniently obtained at one step. transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). By changing the initial molar ratio of arninodextran to platinum precursor, Pt nanoparticles with different size were obtained. Amino groups of aminodextran could absorb on Pt nanoparticles surfaces and serve as a very good stabilizer. However, dextran without amino groups could not effectively stabilize Pt nanoparticles and aggregation of Pt nanoparticles were obtained. Catalytic activity of these Pt nanoparticles for the electron-transfer reaction between hexacyanoferrate (III) ions and thiosulfate ions was also studied, and they showed good catalytic efficiency.

[size=5][b]Selective formation of tetrahedral Pt nanocrystals from K2PtCl6/PVP[/b][/size] H*j7I.]6x-I:T'k
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Yu YT, Xu BQ\ vz},F)B2l2fY

~-nL]-n!sct5g [b][i]CHINESE SCIENCE BULLETIN[/i][/b] 48 (23): 2589-2593 DEC 2003
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Tetrahedral platinum (Pt) nanocrystals (3-8 nm) are synthesized in high selectivity (ca. 80%) from hydrogen reduction of aqueous K2PtCl6 by using polyvinylpyrrolidone (PVP: M(w)approximate to360000) as a protector. Morphology (TEM) measurements of the metal colloids and UV-Vis absorption of the colloidal solution are employed to monitor the tetrahedron formation during the syntheses with varying K2PtCl6/PVP ratios. The results clearly show a two-stage process for the selective formation of tetrahedral nanocrystals. Rapid nucleation and crystal formation at the early stage result in round-like crystallites and the external facet evolution in thereafter slow crystal growth leads selectively to the formation of the tetrahedrons.

[b][size=5]Synthesis of monodisperse Pt nanocubes and their enhanced catalysis for oxygen reduction[/size][/b]x,}0Ix+o:[7Y

YY@+m%aZI Wang C (Wang, Chao), Daimon H (Daimon, Hideo), Lee Y (Lee, Youngmin), Kim J (Kim, Jaemin), Sun S (Sun, Shouheng)

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`3XQI*y\!m+oWV2@ [b][i]JOURNAL OF THE AMERICAN CHEMICAL SOCIETY[/i][/b] [b]129 [/b](22): 6974-+ JUN 6 2007
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Monodisperse 8 nm Pt nanocubes are synthesized by reducing Pt(acac)(2) in the presence of oleic acid, oleylamine, and a trace amount of Fe(CO)(5). Self-assembly of these nanocubes results in a (100) textured array. The nanocubes show an enhanced catalysis toward oxygen reduction, and their specific activity is [color=Red]over twice as high as that from the commercial Pt nanoparticles[/color].K.x+@"Hl2}Ck*o"s
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AU(S!uC m?7S)^ [[i] 本帖最后由 nanosurface 于 2007-09-05 11:16 编辑 [/i]]

[size=5][b]One-dimensional porous carbon/platinum composites for nanoscale electrodes[/b][/size]
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Cui GL (Cui, Guanglei), Zhi LJ (Zhi, Linjie), Thomas A (Thomas, Arne), Kolb U (Kolb, Ute), Lieberwirth I (Lieberwirth, Ingo), Mullen K (Muellen, Klaus) H@mA8a/`,bT
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[b][i]ANGEWANDTE CHEMIE-INTERNATIONAL EDITION [/i][/b][b]46[/b] (19): 3464-3467 2007
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In summary, 1D nanoscale carbon/platinum electrodes with surface areas higher than 1100 m2 g were prepared in a controlled fashion by the combination of a template method with electrochemical procedures. Small platinum nanoparticles with a narrow size distribution were homogeneously dispersed in the interconnected porous carbon matrix. Electrocatalytic characterization demonstrated that these Pt/MPCNTs have excellent catalytic activities in the ORR. The j0 value is about 1000-fold higher than that of commercially available platinum black. This general method should also be suitable for a variety of metal species. The composites, as prepared, are promising candidates for the construction of miniaturized fuel cells and catalytic reactors.dW!{0f'ZY
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[size=5][b]Oxygen reduction at nanostructured electrodes assembled from polyacrylate-capped Pt nanoparticles in polyelectrolyte[/b][/size]
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{5@)h+W/_ f Estephan ZG (Estephan, Zaki G.), Alawieh L (Alawieh, Leen), Halaoui LI (Halaoui, Lara I.)
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/u oR4JyDl:]\!r [b][i]JOURNAL OF PHYSICAL CHEMISTRY C[/i][/b] [b]111[/b] (22): 8060-8068 JUN 7 2007
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;@*upNYy F+~b(n+V Oxygen reduction and related processes are studied at nanostructured Pt electrodes assembled from polyacrylate-capped Pt nanoparticles (< d > = 2.5 +/- 0.6 nm) in poly(diallyldimethylammonium)chloride (PDDA) on indium tin oxide or glassy carbon with varying nanoparticle surface coverage. The nanoparticle density was varied laterally by varying the dipping time of PDDA-modified electrodes in the nanoparticles solution, or vertically with the number of nanoparticle/polyelectrolyte (bi)layers following a layer-by-layer assembly. TEM images revealed submonolayer coverage in one bilayer at 60 min dipping with a fractal distribution, and a significant surface coverage at four bilayers with evidence of multilayer assembly. Cyclic voltammetry in oxygen-containing electrolytes showed the assemblies to be electroactive for oxygen and hydrogen peroxide reduction, with a pH-dependent oxygen reduction peak shifting by -50 mV/pH unit. OH adsorption was found to be less favored occurring at more positive potential at the nanostructured electrode compared to polycrystalline Pt, while the oxide reduction peak was negatively shifted at the former electrode, in agreement with reports of increased oxophilicity with decreased particle size. The oxygen reduction peak potential shifted positively upon increasing Pt nanoparticles coverage, consistent with the catalytic activity of Pt for oxygen reduction. The active surface area of Pt nanoparticles was measured electrochemically from the charge of hydrogen underpotential deposition at the assemblies in H2SO4, and the diffusion-limited peak current for oxygen reduction measured per real Pt surface area is reported to decrease with increasing catalyst loading, as a result of reaching a limiting effective diffusion field.

[size=5][b]Preparation, self-assembly, and mechanistic study of highly monodispersed nanocubes[/b][/size] :good
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Ren JT (Ren, Jintian), Tilley RD (Tilley, Richard D.),q3Z*Hjy~D
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8}6SqQ$pc+X JOURNAL OF THE AMERICAN CHEMICAL SOCIETY[/b][/i] [b]129[/b] (11): 3287-3291 MAR 21 2007
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In this paper, we describe the synthesis and growth mechanism of highly monodispersed platinum nanocubes. The platinum nanocubes are synthesized by the decomposition of a platinum precursor in a hydrogen atmosphere. The morphology and size distribution of the platinum particles formed has been studied with HRTEM. By controlling the concentration of the platinum precursor, we demonstrate that at low concentration, it is possible to grow polydispersed nanocubes with {1,0,0} facets. Increasing the concentration of the precursor changes the growth mechanism, resulting in the formation of highly monodispersed platinum nanocubes. Highly monodispersed platinum nanocubes are formed in a two-step growth mechanism with initial growth of the {1,1,1} facets followed by secondary growth filling the {1,0,0} facets. The particle monodispersity facilitates the formation of long-range arrays of nanocubes. 9RK x{i5b
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[b][size=5]One-step pyrolysis process to synthesize dispersed Pt/carbon hollow nanospheres catalysts for electrocatalysis[/size][/b]
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Song YY (Song, Yan-Yan), Li Y (Li, Ying), Xia XH (Xia, Xing-Hua)
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[b][i]ELECTROCHEMISTRY COMMUNICATIONS[/i][/b] [b]9[/b] (2): 201-205 FEB 2007
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An effective method for loading Pt nanoparticles on monodispersed hollow carbon nanospheres by one-step pyrolysis of polystyrene spheres (PS) adsorbed with platinum (IV) ions was developed. The polystyrene spheres were firstly enwrapped with a layer of sucrose and cetyltrimethyl ammonium bromide (CTAB) micelles. Adsorption of platinum (IV) ions onto the polystyrene spheres was carried out via electrostatic interaction between the negatively charged platinum salt and the positively charged amino group in the CTAB. Pyrolysis of the PS-Pt (IV) precursors at 600 degrees C under nitrogen atmosphere resulted in the simultaneous decomposition of the sucrose to carbon and the adsorbed platinum complex to metallic Pt. During this process the polystyrene spheres was removed and hollow sphere of PtC formed. Nanocomposites of hollow carbon nanospheres with different platinum loading were synthesized and their electrocatalytic activity was evaluated using methanol as a model molecule. Results showed that the as-prepared hollow carbon nanospheres supported platinum catalysts have high electrocatalytic activity and long-term stability towards the oxidation of methanol. The present method is promising for the fabrication of carbon supported platinum catalysts for the direct methanol fuel cell.

[size=5][b]Spatially electrodeposited platinum in polyaniline doped with poly(styrene sulfonic acid) for methanol oxidation[/b][/size]2N?8WT.o7?

/L)ZPXRf Huang LM (Huang, Li-Ming), Tang WR (Tang, Wang-Rung), Wen TC (Wen, Ten-Chin)
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#r{%H1C m*_+yTN^_8Lv [b][i]JOURNAL OF POWER SOURCES[/i][/b] [b]164[/b] (2): 519-526 FEB 10 2007 JzQ'b/s_
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Polyaniline (PANI) can be doped with poly(styrene sulfonic acid) (PSS) via doping-dedoping-redoping process. The specific characteristics of PANI doped with PSS (PANI-PSS) were checked by UV-vis spectroscopy, cyclic voltammetry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). PANI-PSS was found to have spatial structure with minimum degradation products. Platinum can be potentiostatically deposited in a spatial layer of the PANI-PSS as evidenced by electron dispersive element analysis (EDS) and Auger electron spectroscopy (AES). The electrochemical measurements demonstrated that PANI-PSS-Pt exhibited a much higher electrocatalytic activity for methanol oxidation than PANI-Pt.

[size=5][b]Synthesis of nanogroove-network-structured platinum nanosheets and their carbon-supported forms using a mixed-surfactant templating approach[/b][/size] :new
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Sakai G (Sakai, Go), Yoshimura T (Yoshimura, Takumi), Isohata S (Isohata, Shusaku), Uota M (Uota, Masafumi), Kawasaki H (Kawasaki, Hideya), Kuwahara T (Kuwahara, Takeshi), Fujikawa D (Fujikawa, Daisuke), Kijima T (Kijima, Tsuyoshi)j;UDESF]i

#W({R.@,L~ [b][i]ADVANCED MATERIALS[/i][/b] [b]19 [/b](2): 237-+ JAN 20 2007;D,Tuc:pF

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k)ML)y4S$W5g-J Single-crystalline Pt nanosheets with a nanogroove-network structure (see figure) are reported. A method of loading the nanogrooved Pt nanosheets on a carbon support is also described and the resulting nanogroove-networked Pt on a carbon support (Pt/C) is demonstrated to exhibit fairly high electrocatalytic activity for oxygen reduction, which is of interest for fuel cells.

[b][size=5]Synthesis of Pt nanoparticles and nanorods by microwave-assisted solvothermal technique[/size][/b]5@ u%ko\V L4_A

rZ2d"Z5T.|%Y7@@e Li DS (Li, Dongsheng), Komarneni S (Komarneni, Sridhar)0Vk3ZOl3p

_z1e:t&zO2y5Y [b][i] ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES [/i][/b][b]61[/b] (12): 1566-1572 DEC 2006
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'T6b9z3F&L7V Abstract: Platinum nanoparticles and nanorods were synthesized by microwave-assisted solvothermal techniques. Changing the reaction conditions controlled particle size and morphology. The effects of the reaction conditions, such as the molar ratio of the polyvinylpyrrolidone (PVP) repeating unit to the metal sources, the concentration of metal sources, the reaction temperature, and the presence of distilled water were investigated. Nanoparticles of Pt were approximately 3 nm in size. Produced nanoparticles and nanorods were characterized by transmission electron microscopy. Image J(TM) software was used to calculate the particle size and size distribution.

[size=5][b]Photochemical synthesis of crown-shaped platinum nanoparticles using aggregates of G4-NH2 PAMAM dendrimer as templates[/b][/size]
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5dG2hNF5v:w'a FV5A Luo XH (Luo, Xuzhong), Imae T (Imae, Toyoko)
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;B(N6[q2Wk.j [b][i]JOURNAL OF MATERIALS CHEMISTRY[/i][/b] [b]17 [/b](6): 567-571 2007
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Iqnr%Fs(mk7Cj Abstract: Crown-shaped platinum nanoparticles were synthesized by UV irradiation in the presence of G4-NH2 PAMAM dendrimers in water. Aggregates of the dendrimers, which were formed in the aqueous solution, served as templates for the formation of such nonspherical nanoparticles. This is the first report on the preparation of structure-controlled platinum nanoparticles by photoreduction. This methodology to use dendrimer aggregates as templates is powerful for the production of shape-controlled nanostructures.

[b][size=5]Formation mechanism of Pt single-crystal nanoparticles in proton exchange membrane fuel cells[/size][/b]3Dx$q9H3p)]@{t1q`"~

8N#H&wEKc)w5u Ferreira PJ (Ferreira, P. J.), Shao-Horn Y (Shao-Horn, Yang)
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X0z/f ELECTROCHEMICAL AND SOLID STATE LETTERS[/i][/b] [b]10[/b] (3): B60-B63 2007@i"~8t[4Y

n'A7?)q5DBFH6} Abstract: In proton exchange membrane fuel cells, hydrogen permeated from the anode to the cathode was found to reduce soluble Pt species and produce faceted and dendritic Pt nanoparticles in the cathode ionomer. Moving away from the carbon support particles, the morphology of Pt nanoparticles changed from dendritic shapes to truncated tetrahedrons, truncated octahedrons, and truncated square cuboids. Transmission electron microscopy results suggest that the homogeneity of the driving force (supersaturation) for reduction of soluble Pt at the growing surface could dictate the transition from dendritic to faceted growth, and the competition between surface energy and interfacial kinetics of Pt reduction could govern the shape of faceted Pt nanoparticles.

[size=5][b]One-pot dual size- and shape selective synthesis of tetrahedral Pt nanoparticles[/b][/size]
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Kinge S (Kinge, S.), Bonnemann H (Boennemann, H.)
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w*h d g.N]Q#` [b][i]APPLIED ORGANOMETALLIC CHEMISTRY [/i][/b][b]20[/b] (11): 784-787 NOV 2006{q v0sC
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/tby.pU|7I| Abstract: One-pot dual size- and shape-selective synthesis of tetrahedral Pt nanoparticles is achieved using the pre-prepared Pt nanoparticles as the 'external seeds', and controlling the slow diffusional growth under hydrogen reduction in the presence of PVP as the capping agent.

[b][size=5]Pt nanoparticles surfactant-directed assembled into colloidal spheres and used as substrates in forming Pt nanorods and nanowires[/size][/b]
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Chen JY (Chen, Jingyi), Xiong YJ (Xiong, Yujie), Yin YD (Yin, Yadong), Xia YN (Xia, Younan)
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[b][i]SMALL[/i][/b] [b]2[/b] (11): 1340-1343 NOV 2006 1cM!J[}
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In summary, we have synthesized Pt nanowires with controllable lengths by using spherical aggregates of Pt nanoparticles as substrates and by adding different amounts of Pt precursor to the reaction mixture. The spherical aggregates (200 nm in diameter) were, in turn, prepared under the direction of an organic surfactant such as SDS. As an immediate advantage over our previously demonstrated systems, the spherical aggregates were more uniform in size and shape, and could be more than five times smaller in dimension. As a result, these aggregates would provide a larger surface area for the nucleation and growth of Pt nanorods and nanowires. After synthesis, the Pt nanorods and nanowires could also be separated from the substrates through a combination of brief sonication and centrifugation. If necessary, the spherical aggregates could be reused as substrates for additional rounds of nanowire growth. We note that Pt has recently been synthesized as branched nanocrystals by a number of research groups.[9] All these new developments will undoubtedly improve the performance of Pt nanostructures in many industrial applications.
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[b][size=5]Diffusion of platinum ions and platinum nanoparticles during photoreduction processes using the transient grating method[/size][/b]
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Harada M (Harada, Masafumi), Okamoto K (Okamoto, Koichi), Terazima M (Terazima, Masahide)|8o\6}C0\\;C
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[b][i] LANGMUIR [/i][/b][b]22 [/b](22): 9142-9149 OCT 24 2006 CVo1rc@eA|:g
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Abstract: The photoreduction process of PtCl62- to Pt nanoparticles in poly(N-vinyl-2-pyrrolidone) solutions upon UV light irradiation was investigated by monitoring the change in the diffusion coefficient (D). The D values of chemical species during UV irradiation was measured by the laser-induced transient grating (TG) method. The TG signal of the PtCl62-solution before UV irradiation was composed of three kinds of contributions, the thermal grating, the species grating due to the creation of PtCl42-, and the species grating due to the depletions of PtCl62-. Upon UV irradiation of the solution, the species grating signal due to PtCl62- diminished and then the TG signal of Pt nanoparticles gradually appeared. This result indicates that the gradual clustering of Pt-0 atoms into Pt nanoparticles occurs after all PtCl62- ions are photochemically reduced to PtCl42- and subsequently transformed to Pt-0 atoms with a short delay. With increasing time of the UV irradiation, the TG signal intensity increased, while D of the Pt nanoparticles did not change. This suggests that the number of Pt nanoparticles increases, but the size of the Pt nanoparticles with the polymer layer is unchanged, in the course of the UV irradiation.