采用置换法,通过在溶液中引入F^-离子,实现了弱酸性条件下Fe纳米粒子在微米Al粉表面定量、快速地化学沉积,制备出具有核壳结构的Fe/Al微纳米复合粒子。将该复合粒子中的Al核用盐酸溶蚀后得到由纳米Fe粒子组成的空心球壳。利用SEM、EDS、XRD、BET和TG/DSC对产物进行了相应地表征,结果表明,微米Al核表面被一层粒径约为30~60nm的Fe纳米粒子致密包覆,Fe/Al复合粉体的比表面积达到11.993m^2/g较包覆前的1.082m^2/g增加了11倍,且Fe/Al微纳米复合粉体与O2反应的活性明显高于原料Al粉。
Via introducing of F- ions, a kind of core-shell Fe/Al nanocomposite had been prepared by displacement method, in which the micron Al grain were coated in a lay of nanometer Fe particles. When as-prepared Fe/Al nanocomposites were immersed into hydrochloric acid until there was no effervescence, the porous shellshaped products composing of nanometer Fe particles can be obtained. SEM, EDS, XRD, BET and TG/DSC analysis were employed to characterize the samples. Results indicated that Al core were covered by the tightly agglomerated Fe nanoparticles of 30-60nm in size, showing honeycomb-like coarse surface. After coating, the specific surface area has an 11-fold increase from 1. 082 to 11. 993m^2/g. Moreover, the thermal reactivity of Fe/ Al nanocomposites with O2 is obviously higher than that of raw Al powders.