▎ 摘　　要

NOVELTY - Preparing a broadband optical absorbent involves weighing and dissolving metal chloride and hexamethylenetetramine in a solvent for reaction, separating the generated precipitate to obtain nano-scale metal hydroxide powder, and then placing the metal hydroxide powder in a reactor. The interior of the reactor is in an oxygen-free environment. The mixed gas of inert gas and hydrogen is introduced into the reactor for carrying out microwave treatment on the metal hydroxide powder in the reactor to obtain nanoscale metal powder. The oxygen-free environment is maintained in the reactor, introduced a mixed gas of inert gas, hydrogen and carbon source gas into the reactor to obtain the core-shell type composite metal powder coated by the graphene wall. The core-shell composite metal powder coated by the graphene wall is placed in an atmospheric environment, and introduced inert gas to obtain the broadband optical absorbent. USE - Method for preparing broadband optical absorbent. ADVANTAGE - The method prepares the broadband optical absorbent in a simple, cost-effective and eco-friendly manner with high-efficiency optical absorbent.