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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

Schematic illusion of the main steps for forming Pt NWs by TAP.
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Figure 1: Schematic illusion of the main steps for forming Pt NWs by TAP.

Mentions: To make a gel coating film, TiO2 was deposited by dipping Si wafers and carbon cloths into the sol and then only the wafers were spun at 1000 rpm for 30 s. The solution used was prepared with isopropylalcohol (IPA):titanium isopropoxide (TTIP):hydrogen chloride (HCl) with a volume ratio of 170:12:0.4 and stirred for 10 min before aging at room temperature (20°C) for 2 days. The as-synthesized TiO2 films were annealed at 500°C for 8 h in an oxygen atmosphere to obtain well-crystallized anatase TiO2 (step 1 in Figure 1), which could be identified by the grazing-angle X-ray diffraction (XRD) pattern shown in Figure 2.


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)

Schematic illusion of the main steps for forming Pt NWs by TAP.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Schematic illusion of the main steps for forming Pt NWs by TAP.
Mentions: To make a gel coating film, TiO2 was deposited by dipping Si wafers and carbon cloths into the sol and then only the wafers were spun at 1000 rpm for 30 s. The solution used was prepared with isopropylalcohol (IPA):titanium isopropoxide (TTIP):hydrogen chloride (HCl) with a volume ratio of 170:12:0.4 and stirred for 10 min before aging at room temperature (20°C) for 2 days. The as-synthesized TiO2 films were annealed at 500°C for 8 h in an oxygen atmosphere to obtain well-crystallized anatase TiO2 (step 1 in Figure 1), which could be identified by the grazing-angle X-ray diffraction (XRD) pattern shown in Figure 2.

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