Formation mechanism of metal nanoparticles studied by XAFS spectroscopy and effective synthesis of small metal nanoparticles

Recently, we studied and developed two useful synthesis methods of metal nanoparticles. The first system is wet chemical synthesis of gold nanoparticles using fast reduction. The second one is photodeposition of metal nanoparticles on TiO2. The X-ray absorption fine structure (XAFS) study revealed their unique formation mechanisms different from the conventional mechanisms. Furthermore, we designed and synthesized new multidentate protecting ligand having sulfur functional groups to synthesize small gold nanoparticles efficiently.

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► We carried out DXAFS measurement of photodeposition process of Rh on TiO2.
► Rh particles with uniform size were found to be formed on TiO2 surface at a constant rate.
► Also QXAFS measurement of formation process of Au nanoparticles in solution was carried out.
► First, nuclears consisting of four atoms were formed and then they were aggregated.
► To achieve the formation of small and uniform Au nanoparticle, we developed the tetradentate passivant.