▎ 摘　　要

NOVELTY - Dual-branched azobenzene/graphene hybrid energy storage material comprises dual-branched azobenzene grafted on the reductive graphene sheet in array manner and is represented by three-dimensional structure. USE - Dual-branched azobenzene/graphene hybrid energy storage material used for storing solar heat. ADVANTAGE - The dual-branched azobenzene/graphene hybrid energy storage material has energy density of 150 Watt.hour/kg, life of 1000 hours, good thermal stability and good cycling performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing dual-branched azobenzene/graphene hybrid energy storage material, which involves: (A) dissolving 5-aminoisophthalic acid in sodium hydroxide and dissolving N,N-dimethylformamide in water; (B) adding solution of di-tert.-butyl dicarbonate in ice water bath; (C) reacting for 24-30 hours at room temperature; (D) acidifying the reaction product with hydrochloric acid and then diluting with water to one-third of the acidity; (E) filtering and washing precipitate repeatedly with water and brine to obtain amino-protected 5-aminoisophthalic acid solid; (F) adding 5-aminoisophthalic acid in dichloromethane and adding N,N-dimethylformamide dropwise to solution; (G) carrying out reaction at room temperature for 4-8 hours; (H) concentrating product by distillation under reduced pressure; (I) re-dissolving concentrate in dichloromethane; (J) drop-wise adding solution of p-aminoazobenzene-4-sulfonic acid and N,N-diisopropylethylamine in dichloromethane and stirring overnight; (K) extracting reaction product with dichloromethane and aqueous solution of ammonium chloride; (L) drying and recrystallizing from N,N-dimethylformamide to obtain orange solid amino protected di-azobenzene; (M) removing solvent and adding water to adjust the pH value to 8-9; (N) washing organic layer with ethyl acetate; (O) stirring mixture at room temperature for 8-10 hours; (P) extracting and dehydrating mixture with anhydrous sodium sulfate; (Q) spin drying mixture to remove solvent and to obtain the dual-branched azobenzene molecule; (R) dissolving dual-branched azobenzene molecule and the sodium nitrite in deionized water; (S) drop-wise adding mixture to hydrochloric acid solution under ice-cooling for 1-2 hours to obtain a diazonium salt solution; (T) adding obtained diazonium salt solution drop-wise to reduced graphene oxide; (U) reacting for 24-48 hours at room temperature; (V) washing with deionized water and N,N-dimethylmethanamide repeatedly until the filtrate has no absorption peak in the ultraviolet spectrum; and (W) drying to obtain product.