Nanotechnology & Integrated Bio-Engineering Centre (NIBEC), Ulster University , Coleraine, Londonderry BT52 1SA, United Kingdom.
Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST) , Central 2, Umezono 1-1-1, Tsukuba 305-8568, Japan.
ACS Appl Mater Interfaces. 2016 Jul 27;8(29):19012-23. doi: 10.1021/acsami.6b02599. Epub 2016 Jul 13.
Carbon nanotube (CNT) growth has been demonstrated recently using a number of nonmetallic semiconducting and metal oxide nanoparticles, opening up pathways for direct CNT synthesis from a number of more desirable templates without the need for metallic catalysts. However, CNT growth mechanisms using these nonconventional catalysts has been shown to largely differ and reamins a challenging synthesis route. In this contribution we show CNT growth from partially oxidized silicon nanocrystals (Si NCs) that exhibit quantum confinement effects using a microwave plasma enhanced chemical vapor deposition (PECVD) method. On the basis of solvent and a postsynthesis frgamentation process, we show that oxidation of our Si NCs can be easily controlled. We determine experimentally and explain with theoretical simulations that the Si NCs morphology together with a necessary shell oxide of ∼1 nm is vital to allow for the nonmetallic growth of CNTs. On the basis of chemical analysis post-CNT-growth, we give insight into possible mechanisms for CNT nucleation and growth from our partially oxidized Si NCs. This contribution is of significant importance to the improvement of nonmetallic catalysts for CNT growth and the development of Si NC/CNT interfaces.
碳纳米管（CNT）的生长最近已经使用了许多非金属半导体和金属氧化物纳米粒子得到了证明，为直接从许多更理想的模板中合成 CNT 开辟了途径，而无需使用金属催化剂。然而，使用这些非传统催化剂的 CNT 生长机制已被证明有很大的不同，仍然是一个具有挑战性的合成途径。在本贡献中，我们展示了使用微波等离子体增强化学气相沉积（PECVD）方法从部分氧化的硅纳米晶体（Si NCs）生长 CNT。基于溶剂和合成后的碎片过程，我们表明可以很容易地控制 Si NCs 的氧化。我们通过实验确定并通过理论模拟解释，Si NCs 的形态以及必要的约 1nm 壳氧化物对于允许 CNT 的非金属生长至关重要。基于 CNT 生长后的化学分析，我们深入了解了可能的从部分氧化的 Si NCs 中形成 CNT 的成核和生长的机制。本贡献对于提高 CNT 生长的非金属催化剂和开发 Si NC/CNT 界面具有重要意义。
