空心纳米镍@SiO2复合材料的制备及其催化性能

分别在非离子表面活性剂聚醚 L-44、聚醚 L-64、壬基酚聚氧乙烯醚NP-7、脂肪醇聚氧乙烯醚AEO-7、曲拉通 X-100和聚乙二醇十六烷基醚与环己烷构成的反胶束体系中，从硝酸镍出发，经水合肼还原镍离子、正硅酸四乙酯水解包覆、焙烧、还原，得到不同结构的空心二氧化硅包覆镍复合材料Ni@SiO2，通过TEM、XRD表征材料结构和组成。结果显示，当以聚乙二醇十六烷基醚为模板剂时，制备出球形空心Ni@SiO2；以聚醚 L44、聚醚 L64、NP-7、AEO-7和曲拉通 X-100为模板时，制备出管状空心Ni@SiO2。对空心Ni@SiO2-Brij-58形成机理进行了研究。以催化NaBH4还原对硝基苯酚为模型反应，研究了空心Ni@SiO2-Brij-58的催化性能，结果显示15 min内反应完全，对硝基苯酚转化率97.6%。

Synthesis of hollow Ni@SiO2 nanomaterial and its catalytic activity

In the reverse micelle systems formed by cyclohexane and non-ionic surfactants Pluronic L44, Pluronic L64, NP-7, AEO-7, Triton X-10 and Brij-58 respectively, nickel nitrate was added and then reduced with the introduction of hydrazine hydrate, and then coated with silica which was realized by the hydrolysis of TEOS. The products were collected by centrifugation and dried under air and then calcinated under nitrogen atmosphere and reduced by hydrogen flow. The as-synthesized products were characterized by TEM and XRD. The results showed that hollow spherical structure was obtained when Brij-58 was used and hollow tubular materials when Pluronic L44, Pluronic L64, NP-7, AEO-7 and Triton X-100 were used. The formation mechanism was also investigated. The reduction of p-nitrophenol with NaBH4 as model reaction was used to test the catalytic activity of hollow Ni@SiO2-Brij-58. It showed that the conversion rate of p-nitrophenol was 97.6% within 15 min.