Preparation of silver-montmorillonite nanocomposites by reduction with formaldehyde and borohydride

Journal of the Brazilian Chemical Society

Institute of Inorganic Chemistry of the ASCR, Czech Republic¹  Praus, Petr¹  VŠB-Technical University of Ostrava, Ostrava-Poruba, Czech Republic¹  Klementová, Mariana¹  Turicová, Martina¹ 

关键词: silver;    nanocomposites;    montmorillonite;    reduction;    formaldehyde;    borohydride;   

DOI  :  10.1590/S0103-50532009000700021

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

Na-rich montmorillonite (MMT) was intercalated with silver cations, which were subsequently reduced with formaldehyde or sodium borohydride. The silver-montmorillonite nanocomposites were studied by UV-visible spectrometry, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The influence of different reducing agents on the dispersity and size of silver particles deposited on montmorillonite surface was investigated. The reduction with borohydride gives rise to uniformly dispersed silver particles with a narrow particle size distribution from 3 nm to 13 nm. Formaldehyde reduction forms unevenly dispersed particles with a much wider size distribution, ranging from 3 to 100 nm. In addition, some Ag2O particles were found among silver particles prepared with formaldehyde, likely as a result of incomplete reduction. Silver-montmorillonite composites prepared by reduction with borohydride and formaldehyde contain 2.4 wt% and 5.3 wt% of Ag, respectively.

【 授权许可】

Unknown