▎ 摘　　要

NOVELTY - Multi-band composite electromagnetic wave absorbing material comprises tin dioxide containing oxygen vacancies and reduced graphene oxide. The mass ratio of the reduced graphene oxide and the tin dioxide containing oxygen vacancies is 20-30:1. USE - The material is useful in C wave band, X wave band and Ku wave band. ADVANTAGE - The material: has excellent repeatability, and low cost; is environmentally friendly, clean and non-toxic, and easy to be produced in large scale. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the multi-band composite electromagnetic wave absorbing material, comprising (i) dissolving the tin salt in a mixed solution of absolute ethanol and water and fully mixing, adding ethyl orthosilicate into obtain tin/silicon composite gel, sealing and aging, soaking in alkaline solution and stirring, then washing, filtering, drying, grinding and calcining to obtain porous tin dioxide, (ii) mixing and calcining the porous tin(II) oxide with aluminum powder to obtain tin dioxide containing oxygen vacancies, (iii) dissolving tin dioxide and graphene oxide containing oxygen vacancies in deionized water, adding coupling agent, performing hydrothermal treatment, freeze-drying, and calcining to obtain multi-band composite electromagnetic wave absorbing material.