Solar-catalytic membranes constructed by graphene oxide and prussian blue@covalent triazine framework “active mega cubes” for ultrafast water transport

Abstract

Two-dimensional membranes are drawing utmost interest owing to outstanding molecular/ion sieving. However, membrane fouling literally restricts stable permselectivity during continuous filtration. Here we first report ultrafast water transport and solar-cleaning graphene oxide (GO) membranes, which integrate with Prussian Blue@Covalent Triazine Framework (PB@CTF) as “active mega cubes”. The intercalated PB@CTF expands the boundary between GO and mega cube crystal face and endows the membrane with photothermal intensified photocatalytic activity. The membrane exhibited a high and stable permeance for organic molecules (>170 L m −2 h −1 bar −1 , >95% rejection to dyes and antibiotics, ∼40-fold higher than GO membrane) during continuous flow through filtration under 1-sun illumination. The heterogeneous catalytic kinetics confirm the photothermal intensified photocatalytic contribution to foulants degradation. The apparent reaction rate constant ( k ) of GO/PB@CTF-3 membrane reaches 0.140 min −1 , 29-fold higher than GO membrane. The work provides a practical solution to maintaining the stable permselectivity and solar cleaning performances of GO membranes by “active mega cubes”. • PB@CTF “active mega cubes” are first introduced to GO membranes. • The membrane shows ultrafast water/molecules transport and solar-cleaning properties. • “Mega cubes” provide straightforward pathways for fast water transport. • “Active cubes” offer photothermal intensified photocatalytic degradation. • The membrane achieves high permeance and molecules removal continuously.