HRTEM and STXM, a combined study of an individual focused-ion-beam patterned CNT

Carbon nanotubes (CNTs) are either metallic or semiconducting and are unique in terms of their chemical and thermal stability, strength and elasticity. The combination of all these properties is expected to reshape the development of functional devices. However, the relatively low reactivity of the CNT surface presents a challenge for their integration. One approach to tackle this drawback is to tailor the interface reactivity by creating functional CNT surfaces. In this context, a strategy for enhancement of CNT application is the activation of their surface by grafting functional groups. Several strategies relying on random active site creation have been developed to functionalize CNTs [1]. The lack of precise control over the functionalized location renders such methods unsuitable for applications where different sections of the very same CNT need different reactivity. For example, some sections of the CNT can be used to build up electrical contacts and others for anchoring nanostructures or assembling molecules. Recently, site-selective functionalization of CNTs at a nanoscale spatial resolution was shown to be possible. By using focused-ion-beam (FIB) irradiation high-chemical-reactivity segments can be created along the CNT axis via spatially resolved defect generation, followed by mild chemical treatments [2].