Authors: H. Takahashi, T. Mabuchi, S. Yokoyama, K. Tohji
Affilation: Tohoku University, Japan
Pages: 337 - 340
Keywords: well crystallized, uniform, alloy nanoparticles, complexes condition
In the case of usual nanoparticles synthesis method, the as-prepared metallic nanoparticles often exhibited inhomogeneous compositions and multi-crystalline structures, which does not adequate for the industrial applications. Therefore, in this study, to develop the synthesis method for “uniform” and “well-crystallized” alloy nanoparticles, relation between the structure of metal complexes in the aqueous solution and reduction mechanism of these alloy nanoparticles were evaluated. Metal complex conditions in an aqueous solution were expected by the calculation using the critical stability constants. Results of the prediction clearly demonstrated that only the [Pd-EDTA] complex was generated independently in the solution with the pH range of 5 to 10. Therefore, conditions of complexes in solution (pH8) were evaluated by Electro Spray Ionization Time of Fright Mass Spectroscopy (ESI-TOF-MS) and also Extended X-ray Absorption Fine Structure (EXAFS). These results clearly demonstrated that formation of one specific metal complex [Pd-EDTA] in the solution was achieved. By the reduction of these controlled mixed solution, only uniform and well crystallized Pd20Te7 was successfully synthesized, since the formations of metal complexes are restricted to [Pd-EDTA]and [Te-citric acid], respectively.