Method for preparing a polygraphene membrane

1. A method for desalinating salt water for water purification, comprising using the step of filtering salt water through a polygraphene membrane, wherein the polygraphene membrane is porous and is prepared by a process comprising the steps of:

mixing graphite and sodium nitrate into sulfuric acid to form a first mixture;

adding potassium permanganate solution into the first mixture to form a second mixture;

adding hydrogen peroxide solution to the second mixture to form a mixture including soluble manganese ions;

filtering the mixture including soluble manganese ions to form an aqueous suspension;

centrifuging the aqueous suspension;

performing ultrasonication of the suspension to obtain graphene oxide sheets;

acylating the graphene oxide sheets to prepare an acylated graphene oxide sheet; and

polymerizing the acylated graphene oxide sheet to prepare the polygraphene membrane, wherein the acylated graphene oxide sheet is polymerized by mixing with at least one of an amine, an amine derivative, a thiol, a thiol derivative, an amide, and an amide derivative.

2. The method for desalinating salt water for water purification according to claim 1 , wherein the acylated graphene oxide sheet is modified with at least one of silver and titania.

3. The method for desalinating salt water for water purification according to claim 1 , wherein the amine is selected from the group consisting of diamine, diethylamine, dialkylamine, triamines, and bis(hexamethylene)triamine.