Abstract
Carbon nanotubes (CNTs) offer unique properties that have the potential to address multiple issues in industry and material sciences. Although many synthesis methods have been developed, it remains difficult to control CNT characteristics. Here, with the goal of achieving such control, we report a bottom-up process for CNT synthesis in which monolayers of premade aluminum oxide (Al2O3) and iron oxide (Fe3O4) nanoparticles were anchored on a flat silicon oxide (SiO2) substrate. The nanoparticle dispersion and monolayer assembly of the oleic-acid-stabilized Al2O3 nanoparticles were achieved using 11-phosphonoundecanoic acid as a bifunctional linker, with the phosphonate group binding to the SiO2 substrate and the terminal carboxylate group binding to the nanoparticles. Subsequently, an Fe3O4 monolayer was formed over the Al2O3 layer using the same approach. The assembled Al2O3 and Fe3O4 nanoparticle monolayers acted as a catalyst support and catalyst, respectively, for the growth of vertically aligned CNTs. The CNTs were successfully synthesized using a conventional atmospheric pressure-chemical vapor deposition method with acetylene as the carbon precursor. Thus, these nanoparticle films provide a facile and inexpensive approach for producing homogenous CNTs.
Highlights
The synthesis of vertically aligned carbon nanotubes (VA-Carbon nanotubes (CNTs)) on a planar substrate has been established as a method for growing high-quality CNTs with controlled lengths [1,2]
The key aspect of this work was the monolayer assembly of premade Fe3 O4 catalyst and Al2 O3 catalyst support nanoparticles for the synthesis of vertically aligned carbon nanotubes (VA-CNTs)
It has been reported that the synthesis of CNTs with a specific chirality mostly depends on the interactions between the metal catalyst, catalyst support, and hydrocarbon [36,37,38]
Summary
The synthesis of vertically aligned carbon nanotubes (VA-CNTs) on a planar substrate has been established as a method for growing high-quality CNTs with controlled lengths [1,2]. Premade catalyst nanoparticles with controlled densities and sizes can affect the number of nucleation sites and the CNT diameters, respectively [13] Efforts in this field have demonstrated the effective growth of VA-CNT arrays [14,15], but a greater control over particle size and the build-up of catalyst monolayer films is required. Monolayer formation on a substrate that is modified with an organic ligand can increase both the uniformity and particle density on the substrate These features are advantageous, as it has been reported that a high density of catalyst particles is required to grow VA-CNTs [30,31]. The obtained nanoparticle films were successfully applied to catalyze the growth of VA-CNTs
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
