Seawater desalination reverse osmosis membrane with both water flux and boron removal rate and its preparation method thereof

A preparation method thereof for seawater desalination reverse osmosis membrane with both water flux and boron removal rate, comprising the following steps:

• (1) after mixing a carbon nitride sol and deionized water, obtaining a carbon nitride solution by a first stirring, wherein,
• the carbon nitride sol is obtained by alkali treatment of the carbon nitride, the alkali treatment comprising:
• mixing powdered carbon nitride with sodium hydroxide solution with the concentration of 3 mol/L to obtain mixed solution with the concentration of 25 mg/mL of the carbon nitride, heating and stirring the mixed solution for 12 h at 60° C. and carrying out ultrasonic treatment for 1 h every 3 h, subjecting the mixture obtained by heating and stirring into a 3500 Da dialysis bag, changing water for a plurality of times, dialyzing for a plurality of days to neutrality to obtain the carbon nitride sol with specific concentration through the calibrated content;
• (2) mixing the carbon nitride solution obtained by the step (1) with m-phenylenediamine aqueous solution and sodium hydroxide, and obtaining an aqueous solution by a second stirring, wherein the concentration of carbon nitride in the aqueous phase solution in the step (2) is 100-500 mg/L, the concentration of sodium hydroxide in the aqueous phase solution is 0.1 wt %-1.0 wt %;
• (3) after mixing trimesoyl chloride and organic solvent, obtaining an organic liquid phase by a third stirring;
• the steps (2) and (3) can be in any order, irrespective of any sequence;
• (4) immersing a reverse osmotic basement membrane into the aqueous solution obtained by the step (2), and then removing the immersed reverse osmotic basement membrane, rolling dry surface solution with a rubber roller, then immersing into the organic liquid phase obtained in step (3) for interfacial polymerization, and obtaining the reverse osmotic basement membrane after interfacial polymerization;
• and
• immersing the reverse osmotic basement membrane after interfacial polymerization in a n-hexane solvent for standing, and then performing heat treatment and cooling in turn to obtain a seawater desalination reverse osmosis membrane with both water flux and boron removal rate.