Combustion synthesis and stability of nanocrystalline La2O3 via ethanolamine-nitrate process
来源期刊:Journal of Rare Earths2012年第1期
论文作者:龙俞霖 杨骏 李小慈 黄微雅 唐渝 张渊明
文章页码:48 - 52
摘 要:Pure nanocrystalline La2O3 powders were successfully prepared by the combustion method.The effect of ethanolamine-to-nitrate ratio on phase composition and crystallite size of the combustion products was systematically investigated.Pure hexagonal La2O3 powders were almost formed in stoichiometric reaction(ψ=1.15),while metallic La phase was obtained in fuel-rich conditions(ψ≥3.0).The as-synthesized hexagonal La2O3 was found to be chemically unstable in ambient air since a complete transformation to hexagonal La(OH)3 was detected after 24 h exposure to air.The resulting hexagonal La(OH)3 showed an excellent ability to remove water pollutant and could nearly remove 100% of the Congo red at room temperature with a removal capacity of 143.5 mg Congo red/g.The phosphate adsorption data on hexagonal La(OH)3 agreed well with the Langmuir model with the estimated maximum adsorption capacity of 57.8 mg/g.
龙俞霖,杨骏,李小慈,黄微雅,唐渝,张渊明
Department of Chemistry,Jinan University
摘 要:Pure nanocrystalline La2O3 powders were successfully prepared by the combustion method.The effect of ethanolamine-to-nitrate ratio on phase composition and crystallite size of the combustion products was systematically investigated.Pure hexagonal La2O3 powders were almost formed in stoichiometric reaction(ψ=1.15),while metallic La phase was obtained in fuel-rich conditions(ψ≥3.0).The as-synthesized hexagonal La2O3 was found to be chemically unstable in ambient air since a complete transformation to hexagonal La(OH)3 was detected after 24 h exposure to air.The resulting hexagonal La(OH)3 showed an excellent ability to remove water pollutant and could nearly remove 100% of the Congo red at room temperature with a removal capacity of 143.5 mg Congo red/g.The phosphate adsorption data on hexagonal La(OH)3 agreed well with the Langmuir model with the estimated maximum adsorption capacity of 57.8 mg/g.
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