论文部分内容阅读
以Mg(NO3)2.6H2O为镁源,以Al(NO33).9H2O为铝源,采用共沉淀法制备了阴离子型层状材料Mg-Al-CO23-LDHs,并用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)和透射电镜(TEM)对产物进行了表征。探讨了加料方式、插层阴离子的用量以及沉淀反应温度对所形成产物物相等的影响。XRD分析结果显示不同加料方式所制备的产物均具有典型的层状结构特征,其中pH恒定法所合成的产物结晶度更高;红外光谱显示产物中存在插层阴离子CO32-;EDX元素分析结果表明产物组成中含有Mg和Al,且n(镁)∶n(铝)=2.6。上述表征结果说明:加料方式、插层阴离子的用量以及沉淀反应温度对产物的物相没有影响,但对产物的结晶度有一定的影响。当初始原料的配比为n(Mg)∶n(Al)∶n(OH-)∶n(CO32-)=6∶2∶20∶2时,在45℃下完成沉淀反应,再将沉淀于65℃下晶化18h可以得到具有典型层状结构的Mg-Al-CO32-LDHs。
The Mg-Al-CO23-LDHs were synthesized by coprecipitation method using Mg (NO3) 2.6H2O as the magnesium source and Al (NO33) .9H2O as the aluminum source. XRD, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the product. The effects of feeding method, dosage of intercalating anion and precipitation reaction temperature on the products formed were discussed. The results of XRD analysis showed that the products prepared by different feeding methods all had the typical layered structure. The product synthesized by pH constant method had higher crystallinity. The infrared spectrum showed that there was intercalated anion CO32- in the product. The results of EDX elemental analysis The product composition contains Mg and Al, and n (magnesium): n (aluminum) = 2.6. The above characterization results show that: the feeding mode, the amount of intercalated anion and the precipitation reaction temperature have no effect on the product phase, but have a certain impact on the crystallinity of the product. When the ratio of the starting materials is n (Mg): n (Al): n (OH-): n (CO32-) = 6: 2: 20: 2, the precipitation reaction is completed at 45 ° C., The crystallization of Mg-Al-CO32-LDHs with typical lamellar structure can be obtained by crystallization at 65 ℃ for 18h.