Mg-Ni-Al-EDTA柱撑LDHs层状材料的水热合成、结构及性能

Hydrothermal Synthesis,Structural Analysis and Performance of EDTA Pillared Mg-Ni-Al Layered Double Hydroxides(LDHs)

以Mg(NO3)2.6H2O、Ni(NO3)2.6H2O、Al(NO3)3.9H2O和[CH2N(CH2COOH)2]2为原料,采用水热合成法,合成了Mg-Ni-Al三元EDTA柱撑LDHs层状材料。采用ICP、元素分析仪、XRD、FTIR、TG-DSC、SEM等手段对样品进行了表征。探讨了pH值、反应温度、反应时间和原料配比对EDTA柱撑LDHs材料合成的影响。结果表明,在pH=8、反应温度控制在140℃、反应时间为24 h时,可以合成出结构规整、晶形良好、各层间排列紧密有序的含不同比例金属阳离子的EDTA柱撑LDHs材料。Mg-Ni-Al三元EDTA柱撑LDHs层状材料通过层间EDTA对Co2+的螯合作用,可以在较短时间内吸附溶液中的Co2+,去除率在97%以上。pH值、吸附时间、吸附温度、固体投加量及初始Co2+浓度对去除率均有不同程度的影响。

Regular EDTA pillared Mg-Ni-A1 layered double hydroxides （LDHs） were synthesized by hydrothermal method, using Mg（NO3）2-6HzO, Ni（NO3）2＂6H20, Al（NO3）3＂9H20 and [CH2N（CH2COOH）2]： as raw materials. The title samples were characterized by ICP, Elemental Analysis, XRD, IR, TG-DSC, SEM. The effect of pH value, reaction temperature, reaction time and molar ratio of raw materials on the structure of EDTA pillared LDHs was investigated. The results show that EDTA could be intercalated into the interlayer of LDHs and the Mg-Ni-A1- EDTA-LDHs with neat surface topography, good crystallinity, and tight and regular arrangement between layers could be obtained at the reaction systems pH value of 8,the hydrothermal temperature of 140 °C and reaction time of 24 h. The obtained Mg-Ni-A1-EDTA-LDHs can be used to remove more than 97% of Co2＋ from aqueous solution in a short time. And pH value, absorption time, absorption temperature, solid dosage, initial concentration of Co2＋ have different effects on the removal efficiency of Co2＋ from aqueous solutions.