Highly efficient removal of organic pollutants from wastewater using a recyclable graphene oxide membrane intercalated with g-C3N4@TiO2-nanowires

Abstract Membrane fouling has been a major challenge in the practical application of membrane technology for wastewater treatment and purification. In this study, a reusable membrane composed of g-C3N4@TiO2-nanowires modified graphene oxide (GO/CN@TNWs) was successfully fabricated through electrostatic interactions and a vacuum filtration-assisted self-assembly process. The as-fabricated membrane possessed higher photocatalytic activity than the pure TNWs under simulated solar light exposure, attributing to the introduction of GO with high absorption and carrier mobility, and the synergistic effects of TNWs and CN. Furthermore, the π-π stacking interactions between GO and organic pollutant molecules contribute to the excellent enrichment efficiency of GO/CN@TNWs membrane (98.77%) toward tetracycline hydrochloride (TCH). Room-temperature ESR studies indicate that the GO/CN@TNWs membrane can generate more superoxide radical, hydroxyl radical and hole species for photocatalytic degradation. Therefore, the GO/CN@TNWs membrane may be used for TCH removal from waste water and the excellent solar-light-driven photocatalytic performance endows GO/CN@TNWs membrane absorbents with recycling abilities for the realization of large-scale wastewater purification.