UCLA

Carbon nanotube (CNT) and graphene as representative carbon allotropes have attracted considerable attention due to their exceptional properties in mechanical, electrical and thermal aspects. The assemblied CNT such as CNT yarns and sheets are particularly interesting regarding their promising applications in macro-scaled form. This work aims to develop multi-functional CNT assemblies coupling with gold nanocrystals with controllable dimensions. A novel strategy of growing two-dimensional gold nanoplates (2-D AuNPLs) on graphene template is first introduced, through which a comprehensive understanding of controllable growth of 2-D AuNPLs on carbon materials surface is established. Accordingly, large-scale AuNPLs can be homogeneously synthesized on CNT sheets substrate using a one-pot route. A detailed analysis of the crystalline structure of AuNPLs is carried out, which shows a preferential {111} orientation. It further presents hybrid CNT sheet-AuNPLs substrate can serve as a novel flexible surface-enhanced Raman scattering (SERS) substrate with ultrahigh sensitivity.

It is of particular interest to fill foreign materials into hollow cores of carbon nanotube (CNT) due to the feasibility of creating novel structures with innovative properties. Hence, this work introduces a new route to encapsulate one dimensional ultrathin gold nanowires (1-D AuNWs) inside CNTs from their assemblied forms. It utilizes oxygen plasma treatment to open CNT shells together with a wet chemistry method to fill gold atoms. The novelty originates from rapidly opening CNTs and efficiently diffusing gold atoms into the cavity. CNT shells function as protecting layers making ultrathin nanowires highly stable with electron irradiation. Thus, atomic structures of AuNWs are well resolved and systematically investigated under high resolution transmission electron microscope (HRTEM). It further illustrates twins can be created in ultrathin AuNWs with the bombardment of energetic electrons, which is effectively enhance their resistance to high-energy beam irradiation.