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Direct growth of ultra-long platinum nanolawns on a semiconductor photocatalyst.

Shen YL, Chen SY, Song JM, Chin TK, Lin CH, Chen IG - Nanoscale Res Lett (2011)

Bottom Line: A template- and surfactant-free process, thermally assisted photoreduction, is developed to prepare vertically grown ultra-long Pt nanowires (NWs) (about 30-40 nm in diameter, 5-6 μm in length, and up to 80 NWs/100 μm2 in the wire density) on TiO2 coated substrates, including Si wafers and carbon fibers, with the assistance of the photocatalytic ability and semiconductor characteristics of TiO2.TEM analytical results suggest that the Pt NWs are single-crystalline with a preferred ⟨111⟩ growth direction.The interactions between the ions and the electrons in the Pt/TiO2 junction are discussed in this study.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan. samsong@mail.ndhu.edu.tw.

ABSTRACT
A template- and surfactant-free process, thermally assisted photoreduction, is developed to prepare vertically grown ultra-long Pt nanowires (NWs) (about 30-40 nm in diameter, 5-6 μm in length, and up to 80 NWs/100 μm2 in the wire density) on TiO2 coated substrates, including Si wafers and carbon fibers, with the assistance of the photocatalytic ability and semiconductor characteristics of TiO2. A remarkable aspect ratio of up to 200 can be achieved. TEM analytical results suggest that the Pt NWs are single-crystalline with a preferred 〈111〉 growth direction. The precursor adopted and the heat treatment conditions are crucial for the yield of NWs. The photoelectrons supplied by TiO2 gives rise to the formation of nano-sized Pt nuclei from salt melt or solution. The subsequent growth of NWs is supported by the thermal electrons which also generated from TiO2 during the post thermal treatment. The interactions between the ions and the electrons in the Pt/TiO2 junction are discussed in this study.

No MeSH data available.


Related in: MedlinePlus

Ultra-long Pt NWs and their properties: (a) the XRD pattern, (b) the TEM image and EDS results (the Cu signal comes from the Cu grids) and (c) the HRTEM lattice image of the NW in (b) and the corresponding electron diffraction patterns by fast Fourier transform, as well as a illustration showing a FCC crystal with the growth direction along [111].
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Figure 4: Ultra-long Pt NWs and their properties: (a) the XRD pattern, (b) the TEM image and EDS results (the Cu signal comes from the Cu grids) and (c) the HRTEM lattice image of the NW in (b) and the corresponding electron diffraction patterns by fast Fourier transform, as well as a illustration showing a FCC crystal with the growth direction along [111].

Mentions: The XRD pattern and EDS spectrum (Figure 4a,b) demonstrate that the NWs thus produced were pure Pt with an FCC structure without any detectable impurity. For a better understanding of the structure of Pt NWs, a high-resolution transmission electron microscope (HRTEM) image recorded from a Pt NW (Figure 4c) depicts the lattice spacing between the {111} planes of 0.23 nm, which was in agreement with the value in a bulk Pt crystal, suggesting the growth direction of the Pt NWs was along 〈111〉 axes. The inserted electron diffraction pattern constructed by fast Fourier transform (FFT) also verifies this preferred growth direction.


Direct growth of ultra-long platinum nanolawns on a semiconductor photocatalyst.

Shen YL, Chen SY, Song JM, Chin TK, Lin CH, Chen IG - Nanoscale Res Lett (2011)

Ultra-long Pt NWs and their properties: (a) the XRD pattern, (b) the TEM image and EDS results (the Cu signal comes from the Cu grids) and (c) the HRTEM lattice image of the NW in (b) and the corresponding electron diffraction patterns by fast Fourier transform, as well as a illustration showing a FCC crystal with the growth direction along [111].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211474&req=5

Figure 4: Ultra-long Pt NWs and their properties: (a) the XRD pattern, (b) the TEM image and EDS results (the Cu signal comes from the Cu grids) and (c) the HRTEM lattice image of the NW in (b) and the corresponding electron diffraction patterns by fast Fourier transform, as well as a illustration showing a FCC crystal with the growth direction along [111].
Mentions: The XRD pattern and EDS spectrum (Figure 4a,b) demonstrate that the NWs thus produced were pure Pt with an FCC structure without any detectable impurity. For a better understanding of the structure of Pt NWs, a high-resolution transmission electron microscope (HRTEM) image recorded from a Pt NW (Figure 4c) depicts the lattice spacing between the {111} planes of 0.23 nm, which was in agreement with the value in a bulk Pt crystal, suggesting the growth direction of the Pt NWs was along 〈111〉 axes. The inserted electron diffraction pattern constructed by fast Fourier transform (FFT) also verifies this preferred growth direction.

Bottom Line: A template- and surfactant-free process, thermally assisted photoreduction, is developed to prepare vertically grown ultra-long Pt nanowires (NWs) (about 30-40 nm in diameter, 5-6 μm in length, and up to 80 NWs/100 μm2 in the wire density) on TiO2 coated substrates, including Si wafers and carbon fibers, with the assistance of the photocatalytic ability and semiconductor characteristics of TiO2.TEM analytical results suggest that the Pt NWs are single-crystalline with a preferred ⟨111⟩ growth direction.The interactions between the ions and the electrons in the Pt/TiO2 junction are discussed in this study.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan. samsong@mail.ndhu.edu.tw.

ABSTRACT
A template- and surfactant-free process, thermally assisted photoreduction, is developed to prepare vertically grown ultra-long Pt nanowires (NWs) (about 30-40 nm in diameter, 5-6 μm in length, and up to 80 NWs/100 μm2 in the wire density) on TiO2 coated substrates, including Si wafers and carbon fibers, with the assistance of the photocatalytic ability and semiconductor characteristics of TiO2. A remarkable aspect ratio of up to 200 can be achieved. TEM analytical results suggest that the Pt NWs are single-crystalline with a preferred 〈111〉 growth direction. The precursor adopted and the heat treatment conditions are crucial for the yield of NWs. The photoelectrons supplied by TiO2 gives rise to the formation of nano-sized Pt nuclei from salt melt or solution. The subsequent growth of NWs is supported by the thermal electrons which also generated from TiO2 during the post thermal treatment. The interactions between the ions and the electrons in the Pt/TiO2 junction are discussed in this study.

No MeSH data available.


Related in: MedlinePlus