Otro
Dynamical study of ZnO nanocrystal and Zn-HDS layered basic zinc acetate formation from sol-gel route
Registro en:
Journal of Physical Chemistry C. Washington: Amer Chemical Soc, v. 111, n. 8, p. 3253-3258, 2007.
1932-7447
10.1021/jp0662909
WOS:000245005900009
Autor
Briois, V.
Giorgetti, Ch.
Baudelet, F.
Blanchandin, S.
Tokumoto, M. S.
Pulcinelli, Sandra Helena
Santilli, Celso Valentim
Resumen
We have pointed out that zinc based particles obtained from ethanolic solution of a zinc acetate derivative (zinc oxy-acetate, Zn4O(Ac)(6)) are a mixture of nanometer sized ZnO, zinc oxy-acetate, and zinc hydroxide double salt (Zn-HDS). The knowledge of the mechanisms involved in the formation of ZnO and Zn-HDS phases, and the evolution of Zn species in reaction medium was monitored in situ during 14 h by simultaneous measurements of UV-vis absorption and extended X-ray absorption fine structures (EXAFS) spectra. This spectroscopic monitoring was initialized just after the addition of an ethanolic lithium hydroxide solution ([LiOH]/[Zn] = 0. 1) to the reaction medium kept under controlled temperature (40 degrees C). This study points out the first direct evidence of the reaction between ZnO nanoparticles and unreacted zinc oxy-acetate to form a Zn-HDS phase. The dissolution of ZnO and the reprecipitation of Zn-HDS are induced by the gradual release of water mainly produced by ethanol esterification well evidenced by gas chromatography coupled to mass spectroscopy and FT-IR measurements.