超临界流体沉积法制备纳米Cu/SBA-15复合材料

采用超临界流体沉积法，以无机盐Cu(NO₃)₂为前驱物，超临界CO₂为溶剂，乙醇为共溶剂，在压力20 MPa左右、温度 50℃ 条件下将Cu(NO₃)₂沉积到SBA-15介孔分子筛的孔道中。反应完成后，用氢气对前驱物进行还原，得到纳米线和纳米颗粒Cu/SBA-15复合材料。用透射电镜(TEM)和X射线衍射(XRD)对Cu/SBA-15复合材料进行表征，发现在SBA-15孔道内部填充了Cu 纳米线和分散的Cu 纳米颗粒。Cu 纳米线平均直径为6nm，长度为几纳米到几微米，并且沿着孔道生长，能够随着孔道发生弯曲；Cu纳米粒子的平均尺寸为3.2nm，高度分散。同时，实验中还发现，通过控制反应条件，能够控制复合材料中纳米结构的形貌(纳米线或者纳米颗粒) 。实验结果表明，超临界流体沉积法是制备担载型复合材料的有效方法。选择合适的共溶剂可以用超临界CO₂溶解无机盐，并可以通过控制反应条件，控制所制备的复合材料中纳米结构的形貌。

Composite preparation of nano Cu/SBA15 by supercritical fluid deposition

Cu(NO3)2 was deposited into the nano-channels of mesoporous SBA-15 using the supercritical fluid deposition (SCFD) method at a pressure of about 20 MPa and a temperature of 50℃，where supercritical CO2 was employed as the solvent and ethanol as the cosolvent. The subsequent reduction of this composite (Cu(NO3)2/SBA-15) led to copper nanowires and/or nanoparticles dispersed in the channels of SBA-15. The resultant Cu/SBA-15 composites were characterized by means of TEM and XRD. The results showed that Cu nanowires with the mean diameter 6 nm grow and curve along the channels of SBA-15 and their lengths vary from several nanometers to several micrometers；while the Cu nanoparticles with sizes of ～ 3 nm are highly dispersed in the channels. Moreover，it is found that with proper cosolvent，inorganic metallic can be solved in supercritical CO2，and the morphology of copper can be controlled by changing the experimental conditions.