▎ 摘　　要

NOVELTY - A nitrogen-doped graphene-modified seven-copper/copper sulfide composite material comprises hollow nanosphere structure, where the surface of the sphere is uniformly distributed on the nitrogen-doped graphene in a loose porous state. USE - Nitrogen-doped graphene-modified seven-copper/copper sulfide composite material for dye-sensitized solar cell (claimed). ADVANTAGE - The nitrogen-doped graphene-modified seven-copper/copper sulfide composite material has better electrochemical stability and excellent photoelectric performance and catalytic ability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a method for preparing a nitrogen-doped graphene-modified seven-copper/copper sulfide composite material, which involves adding copper nitrate trihydrate and polyvinylpyrrolidone into an ethylene glycol solution, stirring uniformly, adding sodium hydroxide solution and ascorbic acid solution to the solution, placing the solution in a water bath for a water bath reaction, placing the graphene oxide powder in deionized water, and after ultrasonic and magnetic stirring, sequentially adding ammonia water and hydrazine hydrate, placing the solution in a reaction vessel lined with polytetrafluoroethylene, and placing in an oven for hydrothermal reaction, centrifuging the solution and repeatedly centrifuging precipitate with deionized water and ethanol until the supernatant is clear and neutral, and drying the product in a freeze dryer to obtain a nitrogen-doped graphene black powder, sequentially adding copper chloride dihydrate, urea, and hexamethylenetetramine in the solution, and slowly adding an aqueous solution of sodium sulfide and an aqueous solution of nitrogen-doped grapheme, and performing ultrasonic and magnetic stirring treatment, placing the solution in a reaction vessel lined with polytetrafluoroethylene, and placing for hydrothermal reaction, centrifuging the solution, and repeatedly centrifuging precipitate with deionized water and ethanol until the supernatant is clear and neutral, drying the product in a freeze dryer to obtain the finished product (2) a use of nitrogen-doped graphene-modified seven-copper-sulfur/copper sulfide composite material for dye-sensitized solar cell.