PEI-SiO2/GO nanofiltration membrane: Achieved high water permeability and dye rejection rate

Water pollution has long been a significant issue, and the purification of dye wastewater plays a crucial role in addressing this problem. Graphene oxide (GO) has found extensive applications in water treatment due to its unique two-dimensional (2D) structure and a surface rich in a large number of oxygen-containing functional groups. We introduced silica(SiO 2 ) and polyethyleneimine(PEI) into GO to prepare a membrane. The experimental findings revealed that the 3-SiO 2 /GO binary composite membrane achieved a high water permeability of 45.6 L m −2 h −1 bar −1 while maintaining retention, which is nearly four times higher than that of the GO membrane (9.85 L m −2 h −1 bar −1 ).The water permeability of the PEI 0.2 -SiO 2 /GO ternary composite membrane achieved 42.37 L m −2 h −1 bar −1 . The rejection rate for methyl orange dye reached 92.36 %, with similar rejection rates all above 95 % observed for other dyes.