▎ 摘　　要

NOVELTY - Azobenzene-graphene composite material (I) are new. USE - (I) are useful in heterocyclic azobenzene molecules and color-changing encryption and confidentiality and information storage display (all claimed). DETAILED DESCRIPTION - Azobenzene-graphene composite material of formula (I) are new. INDEPENDENT CLAIMS are also included for: (1) preparation of (I); and (2) use of heterocyclic azobenzene molecules in color-changing encryption and confidentiality, and information storage display, where heterocyclic azobenzene molecules are e.g. (E)-4-(thiophen-2-yldiazenyl)aniline, (E)-5-((4-aminophenyl)diazenyl)benzene-1,3-diol, (E)-2-((4-amino-2,6-dimethoxyphenyl)diazenyl)benzenesulfonic acid, (E)-4-((3,5-bis(trifluoromethyl)phenyl)diazenyl)-3,5-dimethoxyaniline, (E)-5-((4-hydroxy-2,6-dimethoxyphenyl)diazenyl)benzene-1,2,3-tricarboxylic acid, (E)-5-((4-amino-2,6-dimethoxyphenyl)diazenyl)isophthalic acid and (E)-3-((4-amino-2,6-dimethoxyphenyl)diazenyl)-1H-pyrazole-4-carboxylic acid.