Effect of low-dose irradiation on the properties of GO and GO membrane

Reduced graphene oxide (rGO) is supposed to have better stability and adsorption properties than graphene oxide (GO). Here, GO was controllable reduced by γ-ray irradiation at low doses of 0–10 kGy. Both physicochemical characteristics and filtration performance of GO/rGO membranes were investigated. The XPS, FTIR and UV spectra data showed that both the types and contents of the oxygen-containing functional groups changed after irradiation, but were not linearly correlated with the dose. The irradiation doses of 2 and 10 kGy were two important points, at which the largest C/O values were found. Although the types of the oxygen-containing functional groups were different, the rGO membranes at 2 and 10 kGy both showed the largest flux and the lowest rejection during the long-term filtration. The performance of the rGO membrane is highly influenced by the content rather than the types of oxygen-containing functional groups. The rGO membrane was more stable than the GO membrane at low GO load during the long-term filtration. The rejections of both dye and ions decreased along running time and adsorption was the main mechanism. Different performances were found for the long and short-term filtration. The balance of flux and rejection, as well as the long-term test should be paid more attention during the application of GO/rGO membranes.