The effects of synthesis pH and hydrothermal treatment on the formation of zinc aluminum hydrotalcites

摘要: Zn/Al hydrotalcites were synthesised by coprecipitation at increasing pH from 6.0 – 14.0, followed hydrothermal treatment 150 oC for 7 days. The materials characterised XRD, STEM, ICP-AES, thermal analysis, infrared spectroscopy and Raman spectroscopy. XRD analysis the samples prepared between 9.0 12.0 showed a pattern typical of hydrotalcite, with c-axis distance ~22.6 A. STEM that preparation affected stability hydrotalcite instability, observed 9.0, favoured formation mixed phases when treated hydrothermally. It was also shown stable starting material increased crystallinity resulted in hexagonal plate shaped particles. ICP-AES ratio pH. Thermal three major weight losses corresponding to loss interparticle water, interlayer water dehydroxylation hydroxide layers decarbonisation region.