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Structural Evolution of Chemically-Driven RuO2 Nanowires and 3-Dimensional Design for Photo-Catalytic Applications.

Park J, Lee JW, Ye BU, Chun SH, Joo SH, Park H, Lee H, Jeong HY, Kim MH, Baik JM - Sci Rep (2015)

Bottom Line: Growth then proceeds by Ru diffusion to the nanoparticles, followed by the diffusion to the growing surface of the nanowire in oxygen ambient, supported by the nucleation theory.The RuO2 branched Au-TiO2 nanowire arrays shows a remarkable enhancement in the photocurrent density by approximately 60% and 200%, in the UV-visible and Visible region, respectively, compared with pristine TiO2 nanowires.Furthermore, there is no significant decrease in the device's photoconductance with UV-visible illumination during 1 day, making it possible to produce oxygen gas without the loss of the photoactvity.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, KIST-UNIST-Ulsan Center for Convergent Materials, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.

ABSTRACT
Growth mechanism of chemically-driven RuO2 nanowires is explored and used to fabricate three-dimensional RuO2 branched Au-TiO2 nanowire electrodes for the photostable solar water oxidation. For the real time structural evolution during the nanowire growth, the amorphous RuO2 precursors (Ru(OH)3 · H2O) are heated at 180 (°)C, producing the RuO2 nanoparticles with the tetragonal crystallographic structure and Ru enriched amorphous phases, observed through the in-situ synchrotron x-ray diffraction and the high-resolution transmission electron microscope images. Growth then proceeds by Ru diffusion to the nanoparticles, followed by the diffusion to the growing surface of the nanowire in oxygen ambient, supported by the nucleation theory. The RuO2 branched Au-TiO2 nanowire arrays shows a remarkable enhancement in the photocurrent density by approximately 60% and 200%, in the UV-visible and Visible region, respectively, compared with pristine TiO2 nanowires. Furthermore, there is no significant decrease in the device's photoconductance with UV-visible illumination during 1 day, making it possible to produce oxygen gas without the loss of the photoactvity.

No MeSH data available.


Related in: MedlinePlus

(a) BF- TEM image near the bottom of the RuO2 nanowire (scale bar 20 nm). (b) HRTEM image of RuO2 nanowire obtained after annealing at 190 °C for 1 hr. (c) Magnified HRTEM image of amorphous RuO2 region and (d) crystalline RuO2 nanoparticles at the interface between the region and nanowire (Fig. b, c and d scale bar 5 nm). Inset in (b,c) show the EDS spectra.
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f3: (a) BF- TEM image near the bottom of the RuO2 nanowire (scale bar 20 nm). (b) HRTEM image of RuO2 nanowire obtained after annealing at 190 °C for 1 hr. (c) Magnified HRTEM image of amorphous RuO2 region and (d) crystalline RuO2 nanoparticles at the interface between the region and nanowire (Fig. b, c and d scale bar 5 nm). Inset in (b,c) show the EDS spectra.

Mentions: The detailed growth mechanism was characterized by bright-field TEM (BFTEM) and HRTEM images, as shown in Fig. 3. Figure 3a is a BFTEM image of a single nanowire grown at 190 °C with a diameter of approximately 30 nm. The HRTEM image and the corresponding fast-Fourier transformed (FFT) of the nanowire reveal highly ordered lattice fringes, demonstrating that the nanowire is a defect-free single crystal (Fig. 3b). The RuO2 nanowire has identified as a tetragonal crystalline (110) phase. In the vicinity of the region where the nanowire starts to be grown, there are some crystallized RuO2 nanoparticles that are ~4 nm in size are clearly seen in the vicinity of the nanowires, while most of the nanoparticles exist as a form of amorphous elsewhere (Fig. 3c,d). Any additional Ru-based crystalline phases except the RuO2 phase, tetragonal crystallographic structure, are not observed. This implies that the nanowires are grown from the amorphous nanoparticles by the direct recrystallization process.


Structural Evolution of Chemically-Driven RuO2 Nanowires and 3-Dimensional Design for Photo-Catalytic Applications.

Park J, Lee JW, Ye BU, Chun SH, Joo SH, Park H, Lee H, Jeong HY, Kim MH, Baik JM - Sci Rep (2015)

(a) BF- TEM image near the bottom of the RuO2 nanowire (scale bar 20 nm). (b) HRTEM image of RuO2 nanowire obtained after annealing at 190 °C for 1 hr. (c) Magnified HRTEM image of amorphous RuO2 region and (d) crystalline RuO2 nanoparticles at the interface between the region and nanowire (Fig. b, c and d scale bar 5 nm). Inset in (b,c) show the EDS spectra.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4493639&req=5

f3: (a) BF- TEM image near the bottom of the RuO2 nanowire (scale bar 20 nm). (b) HRTEM image of RuO2 nanowire obtained after annealing at 190 °C for 1 hr. (c) Magnified HRTEM image of amorphous RuO2 region and (d) crystalline RuO2 nanoparticles at the interface between the region and nanowire (Fig. b, c and d scale bar 5 nm). Inset in (b,c) show the EDS spectra.
Mentions: The detailed growth mechanism was characterized by bright-field TEM (BFTEM) and HRTEM images, as shown in Fig. 3. Figure 3a is a BFTEM image of a single nanowire grown at 190 °C with a diameter of approximately 30 nm. The HRTEM image and the corresponding fast-Fourier transformed (FFT) of the nanowire reveal highly ordered lattice fringes, demonstrating that the nanowire is a defect-free single crystal (Fig. 3b). The RuO2 nanowire has identified as a tetragonal crystalline (110) phase. In the vicinity of the region where the nanowire starts to be grown, there are some crystallized RuO2 nanoparticles that are ~4 nm in size are clearly seen in the vicinity of the nanowires, while most of the nanoparticles exist as a form of amorphous elsewhere (Fig. 3c,d). Any additional Ru-based crystalline phases except the RuO2 phase, tetragonal crystallographic structure, are not observed. This implies that the nanowires are grown from the amorphous nanoparticles by the direct recrystallization process.

Bottom Line: Growth then proceeds by Ru diffusion to the nanoparticles, followed by the diffusion to the growing surface of the nanowire in oxygen ambient, supported by the nucleation theory.The RuO2 branched Au-TiO2 nanowire arrays shows a remarkable enhancement in the photocurrent density by approximately 60% and 200%, in the UV-visible and Visible region, respectively, compared with pristine TiO2 nanowires.Furthermore, there is no significant decrease in the device's photoconductance with UV-visible illumination during 1 day, making it possible to produce oxygen gas without the loss of the photoactvity.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, KIST-UNIST-Ulsan Center for Convergent Materials, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.

ABSTRACT
Growth mechanism of chemically-driven RuO2 nanowires is explored and used to fabricate three-dimensional RuO2 branched Au-TiO2 nanowire electrodes for the photostable solar water oxidation. For the real time structural evolution during the nanowire growth, the amorphous RuO2 precursors (Ru(OH)3 · H2O) are heated at 180 (°)C, producing the RuO2 nanoparticles with the tetragonal crystallographic structure and Ru enriched amorphous phases, observed through the in-situ synchrotron x-ray diffraction and the high-resolution transmission electron microscope images. Growth then proceeds by Ru diffusion to the nanoparticles, followed by the diffusion to the growing surface of the nanowire in oxygen ambient, supported by the nucleation theory. The RuO2 branched Au-TiO2 nanowire arrays shows a remarkable enhancement in the photocurrent density by approximately 60% and 200%, in the UV-visible and Visible region, respectively, compared with pristine TiO2 nanowires. Furthermore, there is no significant decrease in the device's photoconductance with UV-visible illumination during 1 day, making it possible to produce oxygen gas without the loss of the photoactvity.

No MeSH data available.


Related in: MedlinePlus