tailieunhanh - Báo cáo hóa học: " Fabrication and Properties of Ag-nanoparticles Embedded Amorphous Carbon Nanowire/CNT Heterostructures"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Fabrication and Properties of Ag-nanoparticles Embedded Amorphous Carbon Nanowire/CNT Heterostructures | Nanoscale Res Lett 2010 5 1449-1455 DOI s11671-010-9660-8 NANO EXPRESS Fabrication and Properties of Ag-nanoparticles Embedded Amorphous Carbon Nanowire CNT Heterostructures Ke-fan Chen Jian-hua Deng Fei Zhao Guo-an Cheng Rui-ting Zheng Received 22 April 2010 Accepted 24 May 2010 Published online 9 June 2010 The Author s 2010. This article is published with open access at Abstract Carbon nanotubes were subjected to doping with an energetic Ag ion beam and the carbon nanotubes on the top of the array were transformed into amorphous carbon nanowires with embedded Ag-nanoparticles. The field emission characteristics of these nanowires were investigated. The minimum turn-on and threshold fields were and V m respectively which were lower than those of the as-grown carbon nanotubes. This was probably because Ag-nanoparticles embedded in the carbon nanowires reduced the effective work function from to eV. Large doping amounts produced serious structural damage at the top of the nanowires and impaired the field emission characteristics. Keywords Carbon nanotube Nanowire Ion implantation Field emission Introduction Since Iijima s landmark paper on carbon nanotubes CNTs in 1991 1 there has been much research on their fabrications 2 3 excellent physical and chemical characteristics 4 5 and potential applications 6 . Rinzler et al. 7 first reported the field emission characteristics of a single multi-walled CNT and pointed out that they have a very low threshold field Eth which is a applied field at field emission current density of 10 mA cm2 and high-field K. Chen J. Deng F. Zhao G. Cheng R. Zheng Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University 100875 Beijing People s Republic of China e-mail gacheng@ emission current density. The reports of Cheng and Zhou 8 showed that electrons are emitted from the top of CNTs. Field