Effect of sulfur on enhancing nitrogen-doping and magnetic properties of carbon nanotubes
1 Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China
2 Key Laboratory for Advanced Manufacturing by Materials Processing Technology and Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China
Nanoscale Research Letters 2011, 6:77 doi:10.1186/1556-276X-6-77Published: 12 January 2011
Sulfur (S) is introduced as an additive in the growth atmosphere of carbon nanotubes (CNTs) in the range of 940-1020°C. CNT products with distorted sidewalls can be obtained by S-assisted growth. Moreover, many fascinating CNT structures can also be found in samples grown with S addition, such as bamboo-like CNTs, twisted CNTs, arborization-like CNTs, and bead-like CNTs. Compared with CNTs grown without S, more nitrogen-doping content is achieved in CNTs with S addition, which is beneficial for the properties and applications of nitrogen-doped CNTs. In addition, S can also enhance the encapsulation of ferromagnetic materials and thus improve the soft magnetic properties of CNTs, which is favorable to the applications of CNTs in the electromagnetic wave-absorbing and magnetic data storage areas.