▎ 摘　　要

NOVELTY - Graphene quantum dot composite titanium dioxide nanotube photocatalyst comprises titanium dioxide nano-tubes densely covered with many graphene quantum dots on the surface. The average size of graphene quantum dot is 3-5 nm. USE - The photocatalyst is useful in catalytic water decomposition to produce hydrogen (claimed). ADVANTAGE - The photocatalyst: utilizes titanium dioxide nanotubes as framework of titanium dioxide, which has greater rigidity, large specific surface area and does not easy to agglomerate, and reduces excess carbonyl groups and other groups on the surface of the graphene quantum dots in the preparation, effectively exposes photocatalytic active sites; and has high catalytic efficiency. The method: is simple, and suitable for large-scale production; and has high reaction efficiency, few steps, low cost and excellent safety. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene quantum dot composite titanium dioxide nano-tube photocatalyst, (i) dissolving carbohydrates in water, stirring until all are dissolved, and reacting for 2-4 hours to obtain brownish yellow liquid, centrifuging to take the supernatant, adding reducing agent and reducing for 4-6 hours to obtain reduced graphene quantum dots, (ii) dispersing titanium dioxide powder in alkali solution, stirring well and reacting for 20-30 hours, centrifuging, precipitating, washing, and drying to product, acidifying the obtained product 1 for 4-8 hours, centrifuging again to collect the precipitate, washing, and drying to obtain sample b, and calcining the sample b to obtain titanium dioxide nano-tubes, and (iii) mixing and stirring the reduced graphene quantum dots with titanium dioxide nanotubes to composite completely, centrifuging, collecting the precipitate, and washing to obtain final product.