National Institute of Advanced Industrial Science and Technology, 1-1-1, Tsukuba, Ibaraki 305-8565, Japan.
Phys Chem Chem Phys. 2013 Oct 21;15(39):16672-5. doi: 10.1039/c3cp52132j. Epub 2013 Aug 28.
Globular aggregates of carbon nanohorns (CNHs) often contain graphite-like thin sheets (GLSs), and providing different functions to CNHs and GLSs would expand the possible applications of the CNH-GLS aggregates. We show that the GLS edges can be carboxylated selectively by immersing the aggregates in an aqueous solution of H2O2 at room temperature for 1 hour. The presence of carboxyl groups was confirmed by temperature-programmed desorption mass spectroscopy measurements, and their amounts were evaluated using thermogravimetric analysis. The preferential carboxylation of GLSs at their edges was evidenced, after the carboxyl groups were reacted with Pt-ammine complexes, by electron microscopic observation of the Pt atoms at the GLS edges. Since few holes in CNH walls were opened by the short-period H2O2 treatment, there was little carboxylation of CNHs.
碳纳米角的球形聚集体（CNHs）通常含有类石墨薄片（GLSs），为 CNHs 和 GLSs 提供不同的功能将扩展 CNH-GLS 聚集体的可能应用。我们表明，通过将聚集体在室温下的 H2O2 水溶液中浸渍 1 小时，可以选择性地羧化 GLS 边缘。通过程序升温解吸质谱测量确认了羧基的存在，并使用热重分析评估了它们的量。在将羧基与 Pt-氨络合物反应后，通过在 GLS 边缘处的 Pt 原子的电子显微镜观察，证明了 GLS 边缘的优先羧化。由于短周期 H2O2 处理很少打开 CNH 壁上的孔，因此 CNH 的羧化很少。
