Chirality-selective growth of single-walled carbon nanotubes through precise regulation of interfacial behavior

Achieving chirality-controlled growth of single-walled carbon nanotubes (SWCNTs) has been a long-standing challenge with significant implications for advanced applications. However, the preparation of catalysts with unique chirality-selective structures is often complex, and the excellent-performing catalysts typically involve high-melting-point metals and alloys with low catalytic activity, which limits the production of SWCNTs on a large scale. Herein, a unique structure SiO₂@ZrO₂/Fe catalyst for the chirality-selective growth of SWCNTs was prepared via a straightforward hydrothermal method. By employing SiO₂ as support, the interfacial behavior between SiO₂ and ZrO₂ was regulated, which facilitated the formation of a lattice-oxygen enriched phase, monoclinic zirconia. The released lattice oxygen played a crucial role in the in-situ etching of metallic SWCNTs and for the maintaining of quasi-static growth conditions, and it leads to the predominant growth of (10, 9) SWCNTs with an abundance of over 54 %, as these kinds of chiral tubes had the lowest formation energy on the catalyst surface. Both experimental and computational results elucidated the factors contributing to high selectivity, and also revealed the importance of precise regulation of interfacial behavior in the release of lattice oxygen and the quasi-static growth process for chirality-controlled SWCNT production. This strategy opens a new avenue for the controlled growth of SWCNTs with specific chiralities.