近日，日本东京大学中村荣一团队实现了通过电子束激活金刚烷C-H键快速、低温形成纳米金刚石。相关论文于2025年9月4日发表在《科学》杂志上。

金刚石和金刚烷（Ad）共享一个Td对称的碳骨架，但将Ad转化为金刚石一直具有挑战性，因为它需要选择性的碳氢键（C-H）裂解和单体组装成金刚石晶格。该方法不同于传统的高温高压金刚石合成。

研究组在真空中以80至200千电子伏特和100至296开尔文的温度对Ad亚微晶体进行数十秒的电子辐照。该工艺制备了立方晶体结构的无缺陷纳米金刚石（NDs），并伴有氢气的析出。时间分辨透射电镜显示Ad低聚物的初始形成转化为球形Nd。相当大的动力学同位素效应表明，C-H裂解是速率决定的，而测试的其他碳氢化合物不能形成Nd。

附：英文原文

Title: Rapid, low-temperature nanodiamond formation by electron-beam activation of adamantane C–H bonds

Author: Jiarui Fu, Takayuki Nakamuro, Eiichi Nakamura

Issue&Volume: 2025-09-04

Abstract: Diamond and adamantane (Ad) share a Td-symmetric carbon skeleton, but converting Ad to diamond has been challenging because it requires selective carbon-hydrogen (C–H) bond cleavage and monomer assembly into a diamond lattice. Our approach differs from the conventional high-temperature, high-pressure diamond syntheses. We electron-irradiated Ad submicrocrystals at 80 to 200 kilo–electron volts and 100 to 296 kelvin in vacuum for tens of seconds. This process yielded defect-free nanodiamonds (NDs) of cubic crystal structure, accompanied by hydrogen gas evolution. Time-resolved transmission electron microscopy revealed the initial formation of Ad oligomers transforming into spherical NDs. A sizable kinetic isotope effect indicates that C–H cleavage was rate-determining, and other hydrocarbons tested failed to form NDs.

DOI: adw2025

Source: https://www.science.org/doi/10.1126/science.adw2025