Developing outstanding radiation-resistant materials with excellent thermal and mechanical properties and self-healing ability remains a great challenge for advanced nuclear energy systems. Here, we incorporate three-dimensional (3D) carbon nanotube (CNT) networks into iron nanocrystals (Fe NCs) to obtain functional bulk Fe-CNT nanocomposites, exhibiting much higher thermal conductivity and mechanical properties than the Fe NCs without sacrificing strength. Irradiations by energetic helium (He) and krypton ions show that 3D CNT networks act as gigantic-capacity “nano-dustbins” to collect and store He atoms and defects via a “loading-transporting-unloading” mechanism in the grain boundary-CNT (GB-CNT) configuration, thus greatly enhancing their radiation tolerance compared with the Fe NC counterparts. The energetic landscape of interactions of He/defects with the GBs and the Fe-CNT interfaces in the nanocomposites are revealed by first-principles calculations. This work offers a promising strategy for material design of high-performance structural materials for future advanced nuclear reactors.

开发具有出色的热和机械性能以及自修复能力的杰出的抗辐射材料，对于先进的核能系统仍然是一个巨大的挑战。在这里，我们将三维（3D）碳纳米管（CNT）网络合并到铁纳米晶体（Fe NCs）中，以得到功能性的块状Fe-CNT纳米复合材料，与Fe NCs相比，在不牺牲强度的情况下，其导热性和机械性能要高得多。高能氦（He）和k离子的辐照表明3D CNT网络充当巨大容量的“纳米垃圾箱”，通过“晶界CNT”中的“加载-传输-卸载”机制来收集和存储He原子和缺陷。 GB-CNT）配置，因此与Fe NC对应物相比，极大地提高了其辐射耐受性。通过第一性原理计算揭示了He /缺陷与GBs和Fe-CNT界面在纳米复合材料中相互作用的高能态势。这项工作为未来的先进核反应堆的高性能结构材料的材料设计提供了有希望的战略。