Endowing g‐C3N4 Membranes with Superior Permeability and Stability by Using Acid Spacers

Abstract g‐C 3 N 4 membranes were modulated by intercalating molecules with SO 3 H and benzene moieties between layers. The intercalation molecules break up the tightly stacking structure of g‐C 3 N 4 laminates successfully and accordingly the modified g‐C 3 N 4 membranes give rise to two orders magnitude higher water permeances without sacrificing the separation efficiency. The sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO)/g‐C 3 N 4 with a thickness of 350 nm presents an exceptionally high water permeance of 8867 L h −1 m −2 bar −1 and 100 % rejection towards methyl blue, while the original g‐C 3 N 4 membrane with a thickness of 226 nm only exhibits a permeance of 60 L h −1 m −2 bar −1 . Simultaneously, SO 3 H sites firmly anchor nitrogen with base functionality distributing onto g‐C 3 N 4 through acid–base interactions. This enables the nanochannels of g‐C 3 N 4 based membranes to be stabilized in acid, basic, and also high‐pressure environments for long periods.