▎ 摘　　要

NOVELTY - Composite photocatalyst comprises 90-99 wt.% semiconductor titanium dioxide nano-particles and nitrogen-doped graphene (NGR) (remaining amount) as a carrier. The titanium dioxide nano-particles are uniformly distributed on 2D plane of NGR. USE - Used as a composite photocatalyst. ADVANTAGE - The photocatalyst comprising titanium dioxide nano-particles has small particle size, and uniform distribution, high catalytic activity, good stability, and long service life. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the photocatalyst, comprising (i) adding 0.05-0.5 mol/l tetrabutyl titanate into ethanol solution under the stirring condition, slowly adding 0.05-0.5 g/l NGR dispersion liquid in dropwise manner, and uniformly stirring at room temperature in a high pressure reaction kettle, and (ii) reacting for 5-15 hours at 120-220 degrees C, naturally cooling to room temperature, centrifugally separating, washing the solid with distilled water and ethanol, and then drying; (2) a composite platinum-modified photocatalyst comprising 90-99 wt.%'s titanium dioxide, 0.1-1.5 wt.% platinum nano particles and NGR (remaining amount), where the platinum nano-particles are uniformly distributed on the 2D plane of titanium dioxide/NGR composite; and (3) preparing the composite platinum-modified photocatalyst, comprising adding 1-10 mmol/l chloroplatinic acid aqueous solution into titanium dioxide/NGR composite, adding 10-40 vol.% aqueous solution of ethanol, irradiating the material with xenon lamp under magnetic stirring at normal temperature until the deposition is complete, centrifugally separating, and drying the solid product to obtain the finished product.