Catalyst pre-diffusion: An efficient strategy for the construction of COF nanofiltration membranes

Covalent Organic Framework Materials (COFs) nanofiltration (NF) membranes have extensive applications in the field of separation. In this work, high performance TpPa COFs NF membranes were prepared with catalyst pre-diffused strategy. The catalyst pre-diffused method can let catalyst attached to the membrane surface, which can promote the formation of intermediates first, and then form a complete COFs separator layer in 30 min. The optimized membrane possesses an excellent performance of CR permeability of 97.57 L⋅m −2 ⋅h −1 ⋅bar −1 with a rejection of 99.25 % for CR. The dye/salt separation selectivity α was up to 480.16 (EB-T/NaCl). This markedly decreases the reaction duration for membrane production and enhances preparation efficiency. Consequently, the catalyst pre-diffusion strategy offers an innovative approach for the fabrication of COFs nanofiltration membranes.