Nano Res. 2011, 4(4): 334–342 334 Low Temperature Growth of SWNTs on a Nickel Catalyst by Thermal Chemical Vapor Deposition Maoshuai He 1 ( , ), Alexander I. Chernov 2 , Elena D. Obraztsova 2 , Jani Sainio 3 , Emma Rikkinen 1 , Hua Jiang 4 , Zhen Zhu 4 , Antti Kaskela 4 , Albert G. Nasibulin 4 , Esko I. Kauppinen 4, 5 ( , ), Marita Niemelä 1 , and Outi Krause 1 1 Department of Biotechnology and Chemical Technology, School of Science and Technology, Aalto University, P.O. Box 16100, FI-00076 Aalto, Finland 2 A.M. Prokhorov General Physics Institute RAS, 38 Vavilov Street, 119991 Moscow, Russia 3 Department of Applied Physics, School of Science and Technology, Aalto University, P.O. Box 11100, FI-00076 Aalto, Finland 4 Nanomaterials Group, Department of Applied Physics and Center for New Materials, School of Science and Technology, Aalto University, P.O. Box 15100, FI-00076 Aalto, Finland 5 VTT Biotechnology, P.O. Box 1000, FI-02044 Espoo, Finland Received: 24 September 2010 / Revised: 2 November 2010 / Accepted: 28 November 2010 © Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2010 ABSTRACT Single-walled carbon nanotubes (SWNTs) have been grown on a silica-supported monometallic nickel (Ni) catalyst at temperatures ranging from as low as 450 ° C to 800 ° C. Different spectroscopic techniques, such as Raman, photoluminescence emission (PLE), and ultra violet–visible–near infrared (UV–vis–NIR) absorption spectroscopy were used to evaluate the diameter and quality of the SWNTs grown over the Ni catalyst at different temperatures. The analysis revealed that high quality SWNTs with a very narrow diameter distribution were obtained at a growth temperature of 500 ° C. In the PLE and absorption spectra, differences were observed between the SWNTs grown on Ni and those grown on cobalt (Co). This result expands the potential of growing a specific (n, m) tube species with relatively high abundance by tuning the catalyst composition. Furthermore, the prerequisites for the low temperature growth of SWNTs over a monometallic transition metal catalyst have been elucidated. KEYWORDS Single-walled carbon nanotubes, synthesis, low temperature, nickel catalyst 1. Introduction Since their discovery in 1993 [1, 2], single-walled carbon nanotubes (SWNTs) have been the focus of intensive research in nanomaterial science because of their unique electronic and optical properties. These intrinsic properties are sensitive to the SWNT chirality which is identified by the chiral indices (n,m) [3]. Most of the existing SWNT synthesis techniques, such as arc-discharge [1, 2], laser ablation [4], and chemical vapor deposition (CVD) [5] with a growth temperature in the 700–4000 ° C range, have been optimized for bulk production of SWNTs with a wide distribution of (n,m) species. Nevertheless, to revolutionize the field of molecular electronics, it is necessary to directly grow SWNTs with some specific chiralities [6]. Selective synthesis of SWNTs over some bimetallic catalysts, such as CoMo [7], FeRu [8], FeNi [9], or FeCu [10] has Nano Res. 2011, 4(4): 334–342 ISSN 1998-0124 DOI 10.1007/s12274-010-0088-3 CN 11-5974/O4 Research Article Address correspondence to Maoshuai He, maoshuai.he@hut.fi; Esko I. Kauppinen, esko.kauppinen@hut.fi