氧化铕组装碳纳米管的制备和表征

The preparation and characteration of carbon nanotubes assembled with europium oxide

采用化学沉淀法将氧化铕组装在碳纳米管上．碳纳米管在含有Eu3+的硝酸溶液中进行回流,在其表面引入了带负电的官能团,这些官能团能够吸附Eu3+,同时强酸可使碳纳米管的两端开口,金属盐通过毛细作用进入碳管的空腔内,经过滴定、水洗和煅烧制备出Eu2O3组装的碳纳米管．TEM结果表明,氧化铕包覆在碳纳米管表面,外层包覆厚度为4-7 nm,同时3-5 nm链状的氧化铕晶体填充在碳纳米管的管腔中．HRTEM结果表明,碳纳米管的碳碳层的间距为0．34 nm,Eu2O3(222)晶面的晶格间距为0．31 nm．XRD结果表明,复合材料中含有Eu2O3和碳纳米管,晶体大小为11 nm．Zeta电位分析表明,碳纳米管在硝酸中氧化,可在碳纳米管中引入带负电荷的官能团,吸附Eu3+．

A composite of multiwall carbon nanotubes （MWNTs） assembled with europium oxide was synthesized by a simple chemistrcal precipitation method. Refluxing MWNTs in a solution of nitric acid containing Eu^3＋ ions could not only introduce some negative charge functional groups on the surface of MWNTs but also lead to the opening of MWNTs at the tips. The Eu^3＋ could be attached on the surface of MWNTs by the charged groups, and the metal salt could be filled into the cavity of MWNTs. Titrated with ammonia solution, filtered and annealed, the Eu2O3 crystals were assembled on MWNTs successfully. Photographs of TEM showed that a thin layer europium oxide Eu2O3 were coated on the MWNTs and the chainlike Eu2O3 crystals were filled into the cavity of MWNTs. The XRD pattern indicated that the Eu2O3 and MWNTs coexisted in the composite and the crystallite size of Eu2O3 was estimated as 11 nm using the Scherrer equation. The effect of surface oxidation treatment of MWNTs was investigated by zeta potential measurement. Refluxing MWNTs in nitric acid could impart negative charge on the surface of MWNTs and Eu^3＋ could be attached to the surface of MWNTs.