▎ 摘　　要

NOVELTY - Nitrogen-doped photocatalyst composite material comprises 5-20 pts. wt. nitrogen-doped nano titanium dioxide, 2-8 pts. wt. nano zinc oxide, 1-3 pts. wt. graphene, 0.5-3 pts. wt. plant extract nano silver, 0.5-2 pts. wt. dispersant, 0.3- 1.5 pts. wt. film-forming agent and 250-450 pts. wt. deionized water. USE - Nitrogen-doped photocatalyst composite material. ADVANTAGE - The nitrogen-doped photocatalyst composite material has a catalytic effect under visible light, which can remove indoor formaldehyde for a long time. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a nitrogen-doped photocatalyst composite material, which involves: (A) preparing nitrogen-doped nano titanium dioxide; (B) weighing the nitrogen-doped nano-titanium dioxide, nano-zinc oxide, graphene, plant extract, nano-silver, dispersant, film-forming agent, deionized water; (C) stirring at 1000-1500 rpm/min for 2-3 hours to make it mixed uniformly; and (D) dispersing ultrasonically the mixed solution for 3-4 hours to obtain the photocatalyst composite material.