Author(s)

Tran Van Khai^1*, Tran Dai Lam², Le Van Thu³, Hyoun Woo Kim⁴

¹Faculty of Materials Technology, Ho Chi Minh City University of Technology, Ho Chi Minh City, Vietnam.
²Institute of Material Science, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
³Institute of Chemistry-Biology and Professional Documents, Ministry of Public Security, Hanoi, Vietnam.
⁴Division of Materials Science and Engineering, Hanyang University, Seoul, Republic of Korea.

In this research, a highly conductive graphene film was synthesized through the chemical reduction of graphene oxide (RGO) nanosheets followed by thermal treatment at 1100℃ (RGO-1100℃) under H₂ ambient. The as-prepared graphene films were characterized by using X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy, X-ray diffractions, raman spectroscopy, transmission electron microscopy, scanning electron microscopy, atomic force microscopy and by electrical conductivity measurements. The results showed that the thermal treatment efficiently removed residual oxygen-containing functional groups on the surface of the RGO sheets and simultaneously restored the sp² carbon networks in the graphene sheets. As a result, the electrical conductivity of RGO-1100℃ (~210 S/cm) film was greatly improved compared with that of RGO (~24 S/cm) and graphene oxide (4.2 × 10^–4 S/m) films. In addition, the NO₂ gas sensing characteristics of the as-prepared RGO films were studied. The results indicated that RGO films were highly responsive to NO₂ at temperature of 200℃.

Graphene, Graphene Oxide, Graphene-Film, Thermal Reduction

Khai, T. , Lam, T. , Thu, L. and Kim, H. (2015) A Two-Step Method for the Preparation of Highly Conductive Graphene Film and Its Gas-Sensing Property. Materials Sciences and Applications, 6, 963-977. doi: 10.4236/msa.2015.611097.