Controlled reduction and fabrication of graphene oxide membrane for improved permeance and water purification performance

It has been found that moderately reduced graphene oxide (RGO) membrane which was applicable to the field of nanofiltration had both good hydrophilicity and appropriate layer spacing. However, existing GO reduction technologies are usually toxic, complex and uncontrollable. Therefore, it is necessary to seek a green and controllable method to develop the partially RGO membrane (RGOM) which has outstanding water purification ability. In this work, GO laminar membranes (GOM) were prepared via vacuum filter, and L ( +)-ascorbic acid (LAA) was employed as a reduction agent to prepare the RGOM. Subsequently, SEM, XPS, Raman and XRD tests were conducted to characterize the physical and chemical properties of RGOM. Furthermore, the effect of reduction degree on water purification performance was determined. Owing to the combined effect of D-spacing and sp(2)domains with ultralow friction, GOM treated in LAA for 10 min (10-RGOM) exhibited a great water flux of 27.62 L m(-2) h(-1) bar(-1)which was 238% higher than that of GOM and also showed excellent dye rejection. Furthermore, compared with GO, 10-RGOM exhibited better structural stability and superior separation performance in different pH environments.