▎ 摘　　要

NOVELTY - Method for preparing functionalized graphene, involves (i) preparing sulfonated graphene oxide and (ii) using potassium stannate as a tin source, L-cysteine as a sulfur source and cetyltrimethylammonium bromide (CTAB) as a dispersant under hydrothermal conditions, where the tin sulfide crystal is crystallized on the surface of the functionalized graphene and forming the functionalized graphene gas-sensitive material loaded with tin sulfide. USE - The method is useful for preparing functionalized graphene with gas-sensitive performance used in a gas-sensitive ink. ADVANTAGE - The method provides the product with excellent dispersion performance in a solvent. The gas-sensitive ink can quickly adsorb nitrogen dioxide and ammonia molecules, has extremely high sensitivity, is not influenced by the external humidity environment, can be directly written on the common substrates such as glass, paper and cloth without the participation of interdigitated electrodes and adopts rapid, simple, repeatable and easily controllable preparation method. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) the functionalized graphene prepared by the method; and (2) a gas-sensitive ink is prepared by adding the functionalized graphene to an ethanol solution and obtaining the product after dispersion.