One-step synthesis of hydrophobic-reduced graphene oxide and its oil/water separation performance

Graphene oxide (GO) was functionalized to form hydrophobic-reduced graphene oxide (rGO) by a one-step hydrothermal method, and oleylamine was used as both reductant and modifier of GO. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and contact angle measurement were used to determine the successful functionalization and reduction of GO. Results indicated that the color of obtained sample was changed from yellow brown to black, and contact angle between water and the graphene paper was over 130°, which was close to the typical hydrophobic material of PTFE; at the same time, the functionalized rGO can be dispersed in some of the typical organic solvents, such as cyclohexane, chloroform, and benzene, proving that oleylamine was effective for the reduction and functionalization of GO. Based on the results, the possible reactions were proposed. Furthermore, the hydrophobic rGO was assembled to film by filtration, which demonstrated its efficient separation ability for oil/water.