Synthesis of Metal Nanoparticles by Using Polyoxometalates as Photocatalysts and Stabilizers

✍ Scribed by Aristidis Troupis; Anastasia Hiskia; Elias Papaconstantinou

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 146 KB
• Volume: 41
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/1521-3773(20020603)41:11<1911::aid-anie1911>3.0.co;2-0

✦ Synopsis

Formation of colloidal metal nanoparticles is a topic of great interest from a fundamental and practical point of view. [1±4] Metal nanoparticles have been obtained by thermal, [3, 5] photochemical, radiolytic, [7] electrochemical, or sonochemical methods, [9] by using various reagents.

Polyoxometalates (POMs) are well-defined metal ± oxygen cluster anions. [10, 11] Their redox chemistry is characterized by shows peaks of Ru 3p3/2 , Ag 3d , N 1s , Cl 2p (respectively at the binding energy (BE) values of 461.5, 367.2, 399.2, and 197.1 eV) and elemental molar ratios respectively equal to 1.0:1.07:7.63:2.10, that fit with the experimental elemental analysis. TGA measurements show a weight loss of about 33 % in the range 130 ± 270 8C due to the loss of three pyrazine molecules, followed by a two-step demolition (range 270 ± 600 8C) leading to the metals (ca. 32 %). An XRPD spectrum of the massive product 4 was found to be identical to a simulated profile achieved from the single-crystal structure. Red crystals were obtained by slow diffusion of a solution of AgNO 3 in MeCN (3.5 mL, 7.1 Â 10 À3 m) into a brown solution of [RuCl 2 (pyz) 4 ] in TCE (3 mL, 1.9 Â 10 À3 m), by using pure MeCN (1.5 mL) as a spacer between the two solutions.