Graphenated carbon nanotube
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/ff/SEM_of_carbon_nanotubes_with_graphene_foliates_of_varying_density%2C_deposited_via_microwave_plasma_enhanced_CVD.tif/lossy-page1-300px-SEM_of_carbon_nanotubes_with_graphene_foliates_of_varying_density%2C_deposited_via_microwave_plasma_enhanced_CVD.tif.jpg)
Graphenated carbon nanotubes (G-CNTs) are a relatively new hybrid that combines graphitic foliates grown along the sidewalls of multiwalled or bamboo style carbon nanotubes (CNTs). Yu et al.[1] reported on "chemically bonded graphene leaves" growing along the sidewalls of CNTs. Stoner et al.[2] described these structures as "graphenated CNTs" and reported in their use for enhanced supercapacitor performance. Hsu et al. further reported on similar structures formed on carbon fiber paper, also for use in supercapacitor applications.[3] Pham et al. [4][5] also reported a similar structure, namely "graphene-carbon nanotube hybrids", grown directly onto carbon fiber paper to form an integrated, binder free, high surface area conductive catalyst support for Proton Exchange Membrane Fuel Cells electrode applications with enhanced performance and durability. The foliate density can vary as a function of deposition conditions (e.g. temperature and time) with their structure ranging from few layers of graphene (< 10) to thicker, more graphite-like.[6]
The fundamental advantage of an integrated graphene-CNT structure is the high surface area three-dimensional framework of the CNTs coupled with the high edge density of graphene. Graphene edges provide significantly higher charge density and reactivity than the basal plane, but they are difficult to arrange in a three-dimensional, high volume-density geometry. CNTs are readily aligned in a high density geometry (i.e., a vertically aligned forest)[7] but lack high charge density surfaces—the sidewalls of the CNTs are similar to the basal plane of graphene and exhibit low charge density except where edge defects exist. Depositing a high density of graphene foliates along the length of aligned CNTs can significantly increase the total charge capacity per unit of nominal area as compared to other carbon nanostructures.[8]
Ismail et al. [9] investigated a continuous synthesis of bulk cotton-like (aerogel) structure of graphenated carbon nanotubes (G-CNTs) via floating catalyst chemical vapor deposition (FCCVD) method. They analysed how changes in the injection rate of the carbon source influenced G-CNTs formation. Their research revealed that an injection rate of 5 ml/h led to optimal synthesis, resulting in improved electrical conductivity and superior gas-sensing capabilities compared to traditional carbon nanotubes (CNTs). Abdullah et al [10] introduced grapeseed oil as a precursor for G-CNTs hybrids, synthesizing mesoporous three-dimensional (3D) G-CNT aerogels with unique morphological features, such as highly disordered multi-wall carbon nanotube (MWCNT) bundles rounded by graphene foliate structures. Yusuf et al [11] conducted a comparative study of G-CNTs as counter electrodes in dye-sensitized solar cells (DSSCs), demonstrating their superior electrical conductivity and catalytic activity compared to standard carbon nanotubes and even conventional platinum layers. Yusuf et al's investigation [12] also highlighted the excellent conductivity of G-CNT sheets, attributing it to their hybrid structure, which presents them as promising candidates to replace conventional platinum as counter electrodes in DSSCs.
References
[edit]- ^ Yu, Kehan; Ganhua Lu; Zheng Bo; Shun Mao; Junhong Chen (2011). "Carbon Nanotube with Chemically Bonded Graphene Leaves for Electronic and Optoelectronic Applications". J. Phys. Chem. Lett. 13. 2 (13): 1556–1562. doi:10.1021/jz200641c.
- ^ Stoner, Brian R.; Akshay S. Raut; Billyde Brown; Charles B. Parker; Jeffrey T. Glass (2011). "Graphenated carbon nanotubes for enhanced electrochemical double layer capacitor performance" (PDF). Appl. Phys. Lett. 18. 99 (18): 183104. Bibcode:2011ApPhL..99r3104S. doi:10.1063/1.3657514. hdl:10161/10603.
- ^ Hsu, Hsin-Cheng; Wang, Chen-Hao; Nataraj, S.K.; Huang, Hsin-Chih; Du, He-Yun; Chang, Sun-Tang; Chen, Li-Chyong; Chen, Kuei-Hsien (2012). "Stand-up structure of graphene-like carbon nanowalls on CNT directly grown on polyacrylonitrile-based carbon fiber paper as supercapacitor" (PDF). Diamond and Related Materials. 25: 176–9. Bibcode:2012DRM....25..176H. doi:10.1016/j.diamond.2012.02.020.
- ^ Pham, Kien-Cuong; Chua, Daniel H.C.; McPhail, David S.; Wee, Andrew T.S. (2014). "The Direct Growth of Graphene-Carbon Nanotube Hybrids as Catalyst Support for High-Performance PEM Fuel Cells". ECS Electrochemistry Letters. 3 (6): F37–F40. doi:10.1149/2.009406eel.
- ^ Pham, Kien-Cuong; McPhail, David S.; Mattevi, Cecilia; Wee, Andrew T.S.; Chua, Daniel H. C. (2016). "Graphene-Carbon Nanotube Hybrids as Robust Catalyst Supports in Proton Exchange Membrane Fuel Cells". Journal of the Electrochemical Society. 163 (3): F255–F263. doi:10.1149/2.0891603jes. hdl:10044/1/37534. S2CID 100673665.
- ^ Parker, Charles B.; Akshay S. Raut; Billyde Brown; Brian R. Stoner; Jeffrey T. Glass (2012). "Three-dimensional arrays of graphenated carbon nanotubes". J. Mater. Res. 7. 27 (7): 1046–53. Bibcode:2012JMatR..27.1046P. doi:10.1557/jmr.2012.43.
- ^ Cui, Hong-tao; O. Zhou; B. R. Stoner (2000). "Deposition of aligned bamboo-like carbon nanotubes via microwave plasma enhanced chemical vapor deposition". J. Appl. Phys. 88 (10): 6072–4. Bibcode:2000JAP....88.6072C. doi:10.1063/1.1320024.
- ^ Stoner, Brian R.; Jeffrey T. Glass (2012). "Carbon nanostructures: a morphological classification for charge density optimization". Diamond and Related Materials. 23: 130–4. Bibcode:2012DRM....23..130S. doi:10.1016/j.diamond.2012.01.034.
- ^ Ismail, Ismayadi; Mamat, Md Shuhazlly; Adnan, Noor Lyana; Yunusa, Zainab; Hasan, Intan Helina (2019-10-14). "Novel 3-Dimensional Cotton-Like Graphenated-Carbon Nanotubes Synthesized via Floating Catalyst Chemical Vapour Deposition Method for Potential Gas-Sensing Applications". Journal of Nanomaterials. 2019: e5717180. doi:10.1155/2019/5717180. ISSN 1687-4110.
- ^ Abdullah, Hayder Baqer; Irmawati, Ramli; Ismail, Ismayadi; Zaidi, Muhammad Azizan; Abdullah, Ahmad Aimanuddin Amzar (2021-11-11). "Synthesis and morphological study of graphenated carbon nanotube aerogel from grapeseed oil". Journal of Nanoparticle Research. 23 (11): 244. Bibcode:2021JNR....23..244A. doi:10.1007/s11051-021-05363-6. ISSN 1572-896X.
- ^ Yusuf, 11) Yusnita (2021). "A Comparative Study of Graphenated-Carbon Nanotubes Cotton and Carbon Nanotubes As Catalysts For Counter Electrode In Dye-Sensitized Solar Cells". Malaysian Journal of Microscopy. 17 (2): 162–174.
{{cite journal}}
: CS1 maint: numeric names: authors list (link) - ^ Yusuf, Yusnita; Shafie, Suhaidi; Ismail, Ismayadi; Ahmad, Fauzan; Hamidon, Mohd Nizar; Sudhir, Pandey Shyam; Wei, Lei (2023-03-31). "Highly Conductive Graphenated-Carbon Nanotubes Sheet with Graphene Foliates for Counter Electrode Application in Dye-Sensitized Solar Cells". Pertanika Journal of Science and Technology. 31 (3): 1325–1333. doi:10.47836/pjst.31.3.12. ISSN 2231-8526.