| Project/Area Number |
17360314
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Physical properties of metals
|
|---|
| Research Institution | Osaka Prefecture University |
|---|
Principal Investigator |
HORI Fuminobu Osaka Prefecture University, Department of Materials Science, Associate Professor (20275291)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOJIMA Takao Osaka Prefecture Universdy, Department of Materials Science, Assistant Professor (70360047)
IWASE Akihiro Osaka Prefecture Universly, Department of Materia Science, Professor (60343919)
AKITA Tomoki UBIQUITAS, AIST, ユビキタスエネルギー研究部門, UBIQUITAS, AIST (80356344)
TANAKA Singo UBIQUITAS, AIST, ユビキタスエネルギー研究部門, UBIQUITAS, AIST (50357448)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥14,520,000 (Direct Cost: ¥14,100,000、Indirect Cost: ¥420,000)
Fiscal Year 2007: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2006: ¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 2005: ¥6,000,000 (Direct Cost: ¥6,000,000)
|
|---|
| Keywords | mteal / nanoparticle / surface and interface / catalitic activity / positron annihilation / first orinciple calculation |
|---|
| Research Abstract |
Au-Pd binary nanoparticles prepared by sonochemical technique were investigated by the analytical transmission electron microscopy, positron annihilation spectroscopy, zeta-potential, X-ray diffraction and catalytic activity reaction experiments. Also, the first principle calculation of Au/Pd slub model and nano clusters have been performed in order to estimate the stability of Au/Pd interface, its electron density and reactive energy between some molecules and Pd surface of core-shell nanoparticles.
Following conclusions we reached
(1) Au-Pd nanoparticles of same diameter with different thickness ratio of Au-core and Pd-shell were successfully produced by sonochemical reduction method. Alloy nanoparticles with same size of core-shell nanoparticles also have been synthesized by addition of another type of surfactant. Moreover, various kind of irradiation reduction, such as electron, gamma-ray and ion beam, experiments have been performed and successfully synthesized pure Au and Au-Pd nan
… More
oparticles.
(2) It makes clear that Au-Pd nanoparticles synthesized by sonochemical method have perfectly phase separation and surface Pd thin lattice tend to expand. Moreover, it found that expanded Pd-shell lattice epitaxially grows on the fcc Au lattice and with the coherent Au/Pd interface structure.
(3) It found by positron annihilation and zeta potential experiments that this lattice expansion near the surface is related to the surface electronic state of which dose not match between pure Au and Pd bulk.
(4) From the first principle calculations, expanded Pd thin lattice grow on fcc Au lattice is stable around Au/Pd interface and its lattice space becomes narrow as the stacked Pd layers increases.
(5) Another calculation shows following result: in an electronic state of LDOS (local density of state) around surface in core-shell structure it appears that shrinking and up shift of d-band takes places.
We proposed that Pd lattice expansion is a very important factor as the peculiar catalytic activity of core-shell Au-Pd nanoparticle. Less
|
