反应温度和时间对纳米氧化镁形貌和结构的影响

Effect of Synthesis Temperature and Time on the Morphology and Structure of Nano-Magnesium Oxide

以六水合氯化镁（MgCl2·6H2O）为镁源，水合肼（N2H4·2H2O）为沉淀剂，采用化学共沉淀法制备纳米氢氧化镁前驱体煅烧得到分散性良好的不同纳米结构的氧化镁（MgO）纳米片。通过XRD、SEM、TEM对产物的结构和形貌进行分析，初步研究了反应温度和时间对MgO纳米片的形貌和结构影响，分析了MgO多孔纳米片的生长机理。结果表明：25℃，24h下Mg0纳米片大小均一尺寸在20—40nm；当温度升高到100℃，72h生长的多孔MgO纳米片缺陷多，是晶粒相互连接起来的，纳米孔洞在10nm；140oC72h制备的多孔纳米片尺寸均一在100～200Bin。因此可以通过调节反应温度和时间来控制多孔氧化镁纳米片结构。

Mesoporous MgO particles were synthesized by chemical co-precipitation method using MgC12 solution as the magnesium source and hydrazine hydrate as precipitant. The samples were characterized by X- ray diffraction, scanning electron microscopy, transmission electron microscopy. The results showed that MgO nanosheets synthesis at 25 ℃ have uniform size in the 20-40 nm; When the temperature rises to 100 ℃, the mesporous MgO nanosheets have more defects, nanoholes in 10 nm. MgO nannosheets synthesis at 140 ℃ ,72 h have uniform size in the 100-200 nm. A possible formation and crystal growth mechanism of mesoporous MgO is proposed. The MgO nanoflake structure can be controlled by adjustion the reaction temperature and time.