Preparation method and application of porous nano sponge material

The invention provides a preparation method of a porous nano sponge material, which comprises the following steps: immersing a cleaned melamine sponge into a dopamine hydrochloride-tris (hydroxymethyl) aminomethane buffer solution at 30 DEG C, cleaning, and drying to obtain a treated melamine sponge; the preparation method comprises the following steps: mixing guanidine hydrochloride, 1, 6-hexamethylenediamine and sodium phytate in the presence of nitrogen, stirring at 100 DEG C for 2 hours, and introducing one end of a four-neck flask into a hydrochloric acid solution; heating to 160 DEG C, stirring to obtain a guanidine polymer, and adding deionized water to obtain a guanidine polymer aqueous solution; and immersing the treated melamine sponge into a guanidine polymer aqueous solution at 30 DEG C, magnetically stirring, and carrying out vacuum drying at 50 DEG C to obtain the material. The invention also studies the surface morphology structure and surface functional groups of the composite material, and ap