TITLE:
Photoreduction and Thermal Properties of Graphene-Based Flexible Films
AUTHORS:
Gautam Naik, Sridhar Krishnaswamy
KEYWORDS:
Graphene, Graphene Oxide, Photoreduction, Laser
JOURNAL NAME:
Graphene,
Vol.6 No.2,
April
25,
2017
ABSTRACT: In the present study, we report on an efficient method for large-area photoreduction
of graphene oxide flexible films. The laser-based reduction can be carried out in situ and can be tuned to attain the properties required.
A systematic study has been conducted to evaluate the variation of the degree
of reduction with the actual reduction temperature, which is measured using an
infrared thermal camera. Local reduction temperature is varied up to 350°C, and the degree of reduction is measured
using the C/O ratio. The C/O ratio is increased from 2:1 for graphene oxide to
10:1 for reduced graphene oxide. This high degree of reduction is observed at
low temperatures, and also in a short period of time. Thermal conductivity
properties calculated using the temperature distribution shows the in-plane
thermal conductivities of graphene oxide and reduced graphene oxide are a few
orders of magnitude lower than single layer graphene. This can be attributed to
oxygen-defect scattering, and also due to the heat conduction through the thickness
of the sample by way of contact between adjacent flakes. This photoreduction
method provides a way for roll-to-roll scalable production of graphene-based
flexible films.