Available online at www.sciencedirect.com ScienceDirect Materials Today: Proceedings 7 (2019) 798–802 www.materialstoday.com/proceedings 2214-7853 © 2018 Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Nanotech Malaysia 2018. Nanotech Malaysia 2018 Direct exfoliation of graphite and its Raman spectroscopic study Nur Ubaidah Saidin*, Kok Kuan Ying, Choo Thye Foo, Roshasnorlyza Hazan, Mahdi Ezwan Mahmoud Materials Technology Group, Industrial Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor, Malaysia Abstract Direct exfoliating is a safer method for graphene preparation. However, it is important to synthesize a graphene with minimum structural defects since they will influence the properties of the devices. This paper focuses on two types of graphite exfoliation techniques, electrochemical and sonication, for the preparation of graphene oxides. The quality of the graphene oxides was studied using Raman Spectroscopy while the morphology was investigated by field emission scanning electron microscopy (FESEM). The results suggest that the graphene oxides synthesized using the electrochemical technique has the minimum number of layers while graphene oxides obtained from the sonication technique has the minimum defects. © 2018 Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Nanotech Malaysia 2018. Keywords: Electrochemical; sonication; graphene; defect density 1. Introduction Graphene, the thinnest materials today [1], is a single-layer of sp 2 hybridized carbon atoms arranged in a honeycomb crystal lattice. There are various techniques used to synthesize this materials, which can be divided into top-down striping techniques and bottom-up synthesis techniques. Table 1 summarized some of the advantages and disadvantages for some of the techniques that have been developed. Due to its outstanding electronic, mechanical, thermal and chemical properties, graphene has promising applications in various devices such as field effect transistors, electrochemical resonators and photovoltaic devices. Graphene offers a charge carrier mobility exceeding 2.0 × 10 5 cm 2 ·V −1 ·s −1 at room temperature, which is 100 times higher than that of silicon [6] and is known as the strongest materials in the world. Its Young’s modulus is more than 1 TPa [7]. It has good thermal conductivity of 5000 W·mK −1 and demonstrates optical performance with an opacity of 2.3% per layer [8]. However, any structural * Corresponding author. Tel.: +603-8911-2000; fax: +603-8911-2153. E-mail address: ubaidah@nuclearmalaysia.gov.my