▎ 摘　　要

NOVELTY - Preparing two-dimensional nano-magnets comprises (i) adding expanded graphite and sodium nitrite to concentrated sulfuric acid, adding potassium permanganate and stirring, adding deionized water and stirring, adding hydrogen peroxide, filtering, collecting filtrate and washing with hydrochloric acid to obtain graphene oxide; (ii) preparing water-soluble graphene carrier solution to prepare a carboxy-supported water-soluble graphene carrier solution or a sulfonate-supported water-soluble graphene carrier solution; and (iii) diluting water-soluble graphene carrier solution, adding drop-wise aqueous ferric chloride, adsorbing on surface of graphene under the electrostatic adsorption between acid and carboxylate, and adding aqueous sodium borohydride drop-wise, stirring and immobilizing on the surface of graphene. USE - The method is useful for preparing two-dimensional nano-magnets. ADVANTAGE - The nano-magnets has stable solution dispersibility. The method controls magnetism. DETAILED DESCRIPTION - Preparing two-dimensional nano-magnets comprises (i) adding expanded graphite and sodium nitrite to concentrated sulfuric acid at 0-4 degrees C under the condition of magnetic stirring at a speed of 300-500 revolutions/minute, and a mass percentage of 98% after completely dissolving, adding potassium permanganate and stirring at 10-15 degrees C for 2-3 hours, stirring at 35 degrees C for 30 minutes, adding deionized water and stirring at 80-100 degrees C for 30 minutes, adding hydrogen peroxide, filtering, collecting the filtrate and washing with hydrochloric acid to obtain graphene oxide; (ii) preparing water-soluble graphene carrier solution to obtain carboxy-supported water-soluble graphene carrier solution or a sulfonate-supported water-soluble graphene carrier solution; and (iii) diluting water-soluble graphene carrier solution to 0.1-1%, and under stirring conditions with a rotation speed of 100-500 revolutions/minute, adding drop-wise the ferric chloride aqueous solution at a rate of 1-5 drops/10 seconds, where the mass ratio of ferric ions to the graphene carrier solution is 1:2-1: 10 after completing the drop-wise addition, stirring the mixture at a constant speed for 1-2 hours to make ferric ions, adsorbing on the surface of graphene under the electrostatic adsorption between acid and carboxylate, and adding the aqueous sodium borohydride drop-wise at a rate of 1-5 drops/10 seconds, where the molar concentration ratio of the aqueous sodium borohydride to the ferric ions aqueous solution is 2:1-6:1 after dropping, stirring at a constant speed for 1-2 hours, so that ferric ions is precipitated as ferroso ferric oxide nanoparticles under sodium borohydride reduction and immobilized on the surface of graphene to obtain two-dimensional nanometer magneton with ferroso ferric oxide particles immobilized on the surface.