Method for preparing porous aromatic framework membranes based on inorganic salt template method

A method for preparing a porous aromatic framework membrane based on an inorganic salt template, comprising the following steps:

• mixing an inorganic salt template, an alkynyl-containing building unit and a bromine-containing building unit, adding solvent and triethylamine to the mixture, and then adding catalyst under nitrogen protection, and mixing evenly to obtain a mixed solution;
• and
• under nitrogen protection and liquid nitrogen, subjecting the mixed solution to a freeze-vacuum-thaw cycle, then heating the mixed solution to 60-150° C. for 48-96 hours to yield an inorganic salt layer, collecting the inorganic salt layer, and removing inorganic salt from the inorganic salt layer to obtain porous aromatic framework nanosheets, and then processing the porous aromatic framework nanosheets via a pressure-assisted method to obtain a porous aromatic framework membrane,
• wherein the bromine-containing building unit is a bromine-containing organic monomer, the alkynyl-containing building unit is an alkynyl-containing monomer, and the numbers of bromine and alkynyl in the respective monomers are both greater than 1.