Aramid nanofiber and carbonyl iron powder composite aerogel as well as preparation method and application thereof

The invention provides a preparation method and application of an aramid nanofiber and carbonyl iron powder composite material. The preparation method comprises the following steps: dispersing aramid nanofiber and carbonyl iron powder in an ethanol solution according to a mass ratio of 1: (3-7), carrying out ultrasonic liquid phase stripping for 0.5-2 hours, and carrying out vacuum filtration to obtain aramid nanofiber and carbonyl iron powder composite hydrogel; the aramid nanofiber and carbonyl iron powder composite hydrogel is subjected to freeze drying under the vacuum condition, and the aramid nanofiber and carbonyl iron powder composite aerogel is obtained. When the thickness of the aramid nanofiber and carbonyl iron powder composite aerogel prepared by the method is only 1.6 mm, the effective absorption of electromagnetic waves reaches 11.2 GHz, and when the thickness of the aramid nanofiber and carbonyl iron powder composite aerogel is 2.4 mm, the maximum reflection loss of the aramid nanofiber and ca