▎ 摘　　要

In this work, a novel 3D graphene/Fe3O4 (G-Fe3O4) nanocomposite was prepared by a facile one-pot hydrothermal process used to be adulterated into the varnish as an anticorrosive and electromagnetic shielding paint. It is confirmed that the skeleton structure of graphene can effectively inhibit Fe3O4 agglomeration by Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique, and the G-Fe3O4 nanocomposites can be well dispersed in the varnish for a longtime without settling. The graphene/Fe3O4 composite varnish shows excellent corrosion resistance both in city water and seawater, besides its corrosion resistance is also superior to that of ordinary anti-rust paint. Moreover, the electromagnetic shielding test confirms that the as-prepared composite varnish shows well electromagnetic shielding performance. This new type of composite varnish has a broad application prospect to be used as urban exterior wall and ships paint.