School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, China.
J Colloid Interface Sci. 2011 Oct 1;362(1):74-80. doi: 10.1016/j.jcis.2011.06.038. Epub 2011 Jun 23.
In this study, we develop a novel one-step method for synthesis of nickel oxide/silicon dioxide (NiO/SiO(2)) mesoporous composites by using N-hexadecyl ethylenediamine triacetate (HED3A) as structure-directing agent. Besides playing a role in directing the mesophase formation, the anionic surfactant also functions as a chelating agent that binds nickel ions. Ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopic analyses were undertaken to determine the chelating ability between HED3A and nickel ions. By adjusting the molar ratio of Ni(2+)/HED3A in the template solution, a series of mesoporous composites with various NiO contents were obtained after calcination. These composites were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption/desorption. The results showed that the generated NiO nanoparticles were aggregated into clusters with the size less than 20 nm, and the composites retained mesoporous characteristics even with high NiO contents. HRTEM images also revealed the migration and aggregation for NiO nanoparticles during the sintering process. Moreover, the energy-dispersive X-ray spectrum (EDX) results showed a close linear relationship between Ni/Si in the composites and Ni(2+)/HED3A in the templates. This chelating surfactant-assistant encapsulation route has the potential to synthesize diversiform metal oxide/silica mesoporous composites with designated compositions.
在这项研究中，我们开发了一种新颖的一步法，通过使用 N-十六烷基乙二胺三乙酸酯（HED3A）作为结构导向剂来合成氧化镍/二氧化硅（NiO/SiO2）介孔复合材料。除了在介孔形成中起导向作用外，阴离子表面活性剂还作为螯合剂与镍离子结合。采用紫外-可见（UV-vis）和傅里叶变换红外（FTIR）光谱分析确定了 HED3A 与镍离子之间的螯合能力。通过调节模板溶液中 Ni(2+)/HED3A 的摩尔比，在煅烧后可以得到一系列具有不同 NiO 含量的介孔复合材料。这些复合材料通过 X 射线衍射（XRD）、高分辨率透射电子显微镜（HRTEM）和氮气吸附/脱附进行了表征。结果表明，生成的 NiO 纳米颗粒聚集为小于 20nm 的簇，并且即使含有高含量的 NiO，复合材料仍保留介孔特性。HRTEM 图像还揭示了 NiO 纳米颗粒在烧结过程中的迁移和聚集。此外，能谱（EDX）结果表明，复合材料中 Ni/Si 与模板中 Ni(2+)/HED3A 之间存在紧密的线性关系。这种螯合表面活性剂辅助封装路线具有合成具有指定组成的多样化金属氧化物/二氧化硅介孔复合材料的潜力。
