纳米结构氧化镁空心球壳的制备及吸附镍离子性能研究

Preparation of nanostructured MgO hollow microspheres and their adsorptive ability to Ni^(2+)

以Pickering乳液的液滴为模板制备纳米结构MgO空心球壳,用SEM、XRD、BET等对空心球壳进行了表征,探讨了其形成机理,并考察了纳米结构MgO空心球壳对水中Ni2+的吸附性能。结果表明,MgO空心球壳为方镁石结构,比表面积为28m2/g;其平均粒径为63μm,表面由平均宽度为65nm的纳米片层构成。Pickering乳液油水界面的部分MgO通过水化反应转变成Mg(OH)2,复合在未反应的MgO粒子上,形成MgO/Mg(OH)2空心球壳;MgO/Mg(OH)2空心球壳经焙烧后得到纳米结构MgO空心球壳。当纳米结构MgO空心球壳用量为0.4g/L时,溶液(初始浓度25mg/L)中Ni2+的去除率为98.3%。

Nanostructured MgO hollow microspheres were prepared with the droplets of a Pickering emulsion as templates. SEM, XRD and BET methods were used for the characterization of the MgO microspheres. The formation mechanism of the MgO microspheres was proposed. The adsorptive ability of the MgO microspheres to Ni2- was investigated. The results showed that MgO microspheres were of periclase structure and had a specific surface area of 28 m2/g and an average diameter of 63/,m. The surfaces of the MgO mierospheres were made up of nanoflakes with an average thickness of 65 nm. MgO microspheres were formed via a hydration reaction of MgO at the oil/water interfaces. The MgO microspheres had a similar adsorptive ability to Ni2＋ to that of MgO nanoparticles, while were more easily separated from the aqueous solution by simple filtration procedure.