Embedding hexanuclear tantalum bromide cluster {Ta 6 Br 12 } into SiO 2 nanoparticles by reverse microemulsion method

• Published in: Heliyon Vol. 4; no. 6; p. e00654
• Main Authors: Chen, Wanghui, Wilmet, Maxence, Truong, Thai Giang, Dumait, Noée, Cordier, Stéphane, Matsui, Yoshio, Hara, Toru, Takei, Toshiaki, Saito, Norio, Nguyen, Thi Kim Ngan, Ohsawa, Takeo, Ohashi, Naoki, Uchikoshi, Tetsuo, Grasset, Fabien
• Format: Journal Article
• Language: English
• Published: England 01.06.2018
• Subjects: Materials science; Materials chemistry; Nanotechnology
• ISSN: 2405-8440; 2405-8440

Hexanuclear tantalum bromide cluster units [{Ta Br }L ] (i = inner, a = apical, L = ligand OH or H O) are embedded into SiO nanoparticles by a reverse microemulsion (RM) based method. [{Ta Br }Br (H O) ]· H O (noted TBH) and tetraethyl orthosilicate (TEOS) are used as the starting cluster compound and the precursor of SiO , respectively. The RM system in this study consists of the -heptane (oil phase), Brij L4 (surfactants), ethanol, TEOS, ammonia solution and TBH aqueous sol. The size and morphology of the product namely {Ta Br }@SiO nanoparticles are analyzed by HAADF-STEM and EDS mappings. The presence and integrity of {Ta Br } in the SiO nanoparticles are evidenced by EDS mapping, ICP-OES/IC and XPS analysis. The optical properties of {Ta Br }@SiO nanoparticles are analyzed by diffuse reflectance UV-vis spectroscopy, further evidencing the integrity of the embedded {Ta Br } and revealing their oxidation state. Both {Ta Br } and {Ta Br } are found in SiO nanoparticles, but the latter is much more stable than the former. The by-products in this RM-based synthesis, as well as their related factors, are also discussed.