Reduced graphene oxide (rGO) with tunable conductivity has great promise for potential applications in the fields of advanced structural-functional composites

new chemical materials and so on. In this research

environment-friendly hydrothermal method was applied to prepare rGO. The conductivity of the synthesized rGO can be controlled from 10-4 to 1 S·cm-1 by changing the hydrothermal reaction temperature and time. Various characterization techniques such as UV-vis

FT-IR

XPS

SEM

XRD

and Raman spectroscopy were used to analyze the composition and structure change of the rGO. The results showed that the oxygen contained functional groups on the rGO surface decomposed rapidly at ≥ 120℃

and the content of oxygen contained functional groups decreased drastically at ≥ 140℃. Meanwhile

the carbon sp2 region of the rGO was recovered gradually

which caused the conductivity increased to 1 S·cm-1 and the interlayer spacing decreased from 8.2 Å to 3.6 Å. Compared with thermal reduction method

hydrothermal method avoids the aggregation and stacking of the rGO

which has great significance in large-scale production of the rGO with tunable conductivity.