Since 2004, graphene has risen in popularity owing to its superior properties. However, limits to the scale of production methods have rendered graphene a costly material. Moreover, existing production methods require chemicals that are detrimental to the environment. This study uses Coconut Coir Dust (CCD) as a carbon precursor and an intermediate product in the manufacturing of graphene. Firstly, CCD sieved into a 100 mesh was carbonized using a hydrothermal method at temperatures of 235oC, 250oC, and 265oC, for 4 hours. Following this, the resulting solid residue was pyrolyzed at 1000oC for 2 hours under the protection of nitrogen (N2). The hydrothermal solid residue was labelled CHT (hydrothermal temperature) and the pyrolysis product was named as SP (hydrothermal temperature). Both samples were characterized using SEM, XRD and EDS. In addition, Raman characterization was conducted for SP samples. At the end of the process (SP), the XRD pattern showed two broad peaks centered around 2? ~24o and 44o corresponding to a (002) and (100) graphite plane. This pattern is similar to that of reduced-graphene oxide. SEM images showed a sheet-like microstructure is caused by undegraded lignin. A perforated and corrugated sheet formed after pyrolysis, which subsequently confirms the formation of reduced-graphene oxide. Furthermore, the Raman result indicates that higher hydrothermal temperatures lead to an increasing integrated ID/IG ratio. The ratios were 1.62, 1.71 and 1.77, for SP 235, SP 250, and SP 265, respectively. Research results conclude that the carbonaceous material formed through hydrothermal and pyrolytic processes contained a mixture of an amorphous-carbon form and a graphene-like cluster. Results additionally show a similar structure with reduced-graphene oxide.

Carbonization; Graphene; Hydrothermal; Pyrolysis; Reduced Graphene Oxide

Coconut coir dust exhibits a complex carbonization reaction when undergoing hydrothermal and pyrolytic treatment. The final carbon content for SP 235, SP 250, and SP 265 was ~93% atom. The crystal structure of carbon was furthermore determined by XRD, which illustrated the formation of a reduced-graphene oxide-like structure. The SEM images used in this paper confirm findings by showing the corrugated morphology of SP samples. For the purposes of comparison, commercial graphene was also tested using Raman, which showed a more nano-crystalline, graphene-like domain. Final investigations using Raman spectroscopy showed that SP 265 exhibited the smallest average crystallite size, with a more graphene-like domain being formed. However, this material requires further purification to separate graphene-like carbon and other amorphous carbon forms that are contained in the SP sample.

This research was funded by the Ministry Research Technology and Higher Education through the Konsorsium Sistem Inovasi Nasional Research Grant, with the contract no. 278/SP2H/LT/DRPM/III/2016. The facilities used in this study were supported by the Centre for Science and Technology for Advanced Materials and the National Nuclear Energy Agency, Indonesia.

Allen, M.J., Tung, V.C., Kaner, R.B., 2010. Honeycomb Carbon?: A Review of Graphene. Chemical Reviews, Volume 110(1), pp. 132–145

Balachandran, M., Ag, K., 2012. Study of Stacking Structure of Amorphous Carbon by X-Ray Diffraction Technique. International Journal of Electrochemical Science, Volume 7, pp. 3127–3134

Barin, G.B., Santos, Y.H., Rocha, J.A., Barreto, L.S., 2013. Graphene-like Nanostructure Obtained from Biomass. Materials Research Society Symposia Proceedings, Volume 1505

Blanton, T.N., Majumdar, D., Company, E.K., 2013. Characterization of X-Ray Irradiated Graphene Oxide Coatings using X-Ray Diffraction, X-Ray Photoelectron Spectroscopy, and Atomic Force Microscopy. JCPDS - International Centre for Diffraction Data, pp. 116–122

Dinjus, E., Kruse, A., Troger, N., 2011. Hydrothermal Carbonization – 1. Influence of Lignin in Lignocelluloses. Chemical Engineering & Technology, Volume 12, pp. 2037–2043

Falco, C., Baccile, N., Titirici, M.-M., 2011. Morphological and Structural Differences between Glucose, Cellulose and Lignocellulosic Biomass Derived Hydrothermal Carbons. Green Chemistry, 13(11), pp. 3273–3281 

Fu, C., Zhao, G., Zhang, H., Li, S., 2013. Evaluation and Characterization of Reduced Graphene Oxide Nanosheets as Anode Materials for Lithium-ion Batteries. International Journal of Electrochemical Science, Volume 8, pp. 6269–6280

Funke, A., Zieglier, F., 2010. Hydrothermal Carbonization of Biomass: A Summary and Discussion of Chemical Mechanism for Process Engineering. Biofuels, Bioproducts, and Biorefining, Volume 4(2), pp. 160–177

Geim, A.K., Novoselov, K.S., 2007. The Rise of Graphene. Nature Materials, Volume 6, pp. 183–191

Honggowiranto, W., Kartini, E., 2016. Characterization of LiFePO4 Cathode by Addition of Graphene for Lithium Ion Batteries. In: AIP Conference Proceedings, Volume 1710(1), pp. 1–8

Jawhari, T., Roid, A., Casado, J., 1995. Raman Spectroscopic Characterization of Some Commercially Available Carbon Black Materials. Carbon, Volume 33(11), pp. 1561–1565 

Kaniyoor, A., Ramaprabhu, S., 2012. A Raman Spectroscopic Investigation of Graphite Oxide Derived Graphene a Raman Spectroscopic Investigation of Graphite Oxide Derived Graphene. In: AIP Advances, Volume 2(3), pp. 1–13

Luo, J., Genco, J., Cole, B., Fort, R., 2011. Lignin Recovered from the Near-neutral Hemicellulose Extraction Process as a Precursor for Carbon Fiber. Bioresources, Volume 6(4) pp. 4566–4593

Mcdonald-wharry, J., Manley-harris, M., Pickering, K., 2013. Carbonisation of Biomass- Derived Chars and the Thermal Reduction of a Graphene Oxide Sample Studied using Raman Spectroscopy. Carbon, Volume 59, pp.383–405

Muramatsu, H., Kim, Y.A., Yang, K-S., Cruz-Silva, R., Toda, I., Yamada, T., Terrones, M., Endo, M., Hayashi, T., Saitoh, H., 2014. Rice Husk-Derived Graphene with Nano-Sized Domains and Clean Edges. Small, Volume 10(14), pp. 2766–2770

Poletto, M., Junior, H.L.O., Zattera, A.J., 2014. Native Cellulose: Structure, Characterization and Thermal Properties. Materials, Volume 7(9), pp. 6105–6119

Rahayu, L.H., Purnavita, S., Sriyana, H.Y., 2014. Coconut Coir and Coconut Potency as Adsorbent for Oil Regeneration (Potensi Sabut dan Tempurung Kelapa sebagai Adsorben untuk Meregenerasi Minyak Jelantah). Momentum, Volume 10(1), pp. 47–53 (in Bahasa)

Reza, M.T., Uddin, M.H., Lynam, J.G., Hoekman, S.K., Coronella, C.J., 2014. Hydrothermal Carbonization of Loblolly Pine?: Reaction Chemistry and Water Balance. Biomass Conversion and Biorefinery, Volume 4(4), pp. 311–321

Sadezky, A., Muckenhuber, H., Grothem H., Niessner, R., Poschl, U., 2005. Raman Microspectroscopy of Soot and Related Carbonaceous Materials?: Spectral Analysis and Structural Information. Carbon, Volume 43(8), pp. 1731–1742

Schwan, J., Ulrich, S., Batori, V., Ehrhardt, H., Silva, S.R.P., 1996. Raman Spectroscopy on Amorphous Carbon Films. Journal of Applied Physics, Volume 80(1), pp. 440–447

Sevilla, M., Fuertes, A.B., 2009. The Production of Carbon Materials by Hydrothermal Carbonization of Cellulose. Carbon, Volume 47(9), pp. 2281–2289

Sofyan, N., Putro, D.Y., Zulfia, A., 2016. Performance of Vanadium-Doped LiFePO4/C used as a Cathode for a Lithium Ion Battery. International Journal of Technology, Volume 7(8), pp. 1307–1315