Hydrothermal Synthesis of Pure-Phase Copper Silicate Na2Cu2Si4O11·2H2O with Ammonia as Complexing Agent

✍ Scribed by Qizhou Jiang; Qi Shi; Hong Xu; Jinping Li; Jinxiang Dong

• Book ID: 102827180
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 610 KB
• Volume: 2011
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.201001002

✦ Synopsis

Abstract

Pure‐phase copper silicate, Na~2~Cu~2~Si~4~O~11~·2H~2~O (AV‐23), was synthesized hydrothermally by starting with a molar ratio of CuO:3.2SiO~2~:3.02Na~2~O:4.57NH~3~:146H~2~O. To avoid the formation of polycrystalline CuO, aqueous ammonia was used as complexing agent. The inductively coupled plasma atomic emission spectroscopy ICP‐AES, XRD, and SEM measurements of the precursors indicated that the sequence in which the starting materials are added can effectively adjust the competition between precipitation and complexation, and consequently the alkali balance in the solution, as copper is present in the form of both Cu(OH)~2~ and [Cu(NH~3~)~4~]^2+^. This adjustment optimizes the distribution of the precursor, which influences the morphology of Cu(OH)~2~. The kinetics of the crystallization is thus affected in such a way that prevents the formation of impure phases.