▎ 摘　　要

NOVELTY - Nitrogen-doped graphene quantum dot/mesoporous titanium dioxide photocatalyst comprises nitrogen doped graphene quantum dot distributed in the surface of titanium dioxide solid microballoon. The nitrogen doped graphene quantum dot/mesoporous titanium dioxide is spherical with diameter 400-600 nanometer,having mesoporous structure. The titanium dioxide is pure anatase titanium dioxide. USE - Nitrogen-doped graphene quantum dot/mesoporous titanium dioxide photocatalyst. ADVANTAGE - The nitrogen-doped graphene quantum dot/mesoporous titanium dioxide photocatalyst is prepared in simple, short and easy to control manner. The hydrogen-producing rate of the material reaches to 0.5 millimolar/hour. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing nitrogen-doped graphene quantum dot/mesoporous titanium dioxide photocatalyst which involves: (A) dissolving citric acid and nitrogen source in molar ratio of 1:3 in proper de-ionized water to obtain neutral mixed solution; (B) ultrasonically dispersing neutral mixed solution; (C) transferring neutral mixed solution to the hydrothermal reaction kettle where it is heated to 140-180 degrees C for 4 hours; (D) washing and drying the product to obtain nitrogen-doped graphene quantum dot using nitrogen source thiourea or urea; (E) dissolving hexadecyl amine in ethanol solution with stirring; (F) adding nitrogen-doped graphene quantum dot dissolved in de-ionized water; (G) ultrasonicating mixture; (H) adding potassium chloride solution and isopropyl titanate; (I) filtering reaction solution; (J) washing product with anhydrous ethanol; (K) drying to obtain nitrogen-doped graphene quantum dot/titanium precursor; (L) dissolving obtained product in mixed solution of absolute ethanol and de-ionized water; (M) heating at 160 degrees C for 16 hours; (N) cooling the reaction product to room temperature; (O) filtering the solution; (P) washing residue; (Q) drying to obtain nitrogen-doped graphene quantum dot/medium titanium dioxide microsphere; and (R) heating nitrogen-doped graphene quantum dot/medium titanium dioxide microsphere in inert atmosphere to obtain nitrogen-doped graphene quantum dot/mesoporous titanium dioxide photocatalyst.