▎ 摘　　要

Through a facile self-assembled process, an ultralight reduced graphene oxide/black phosphorus (rGO/BP) composite aerogel was successfully fabricated. The BP nanosheets were homogeneously distributed throughout the rGO 3D framework, and the interfaces between rGO and BP possessed four kinds of interconnections, such as wrapping, wearing, bridging and weak linking. As an ultralight composite, the rGO/BP aerogel could easily stand on the stamen of a flower. Compared with pure rGO aerogel, the rGO/BP composite aerogel exhibited enhanced microwave absorption ability. The minimum reflection loss value of -46.9 dB with a thickness of 2.53 mm was obtained, and a wide absorption band of 6.1 GHz (RL < -10 dB) was achieved. The superior microwave absorption property was demonstrated to stem from the interfacial polarization loss mechanism in which the multiform interface interactions between the rGO skeleton and BP nanosheets played critical roles. The rGO/BP aerogel has great potential to be used as an ultralight microwave absorber.