▎ 摘　　要

NOVELTY - Graphene sieve photocatalyst comprises nitrogen-doped titanium oxide nanotubes are used as the main catalyst and the graphene sieve is used as the co-catalyst. The preparation includes preparing graphene oxide by electrochemical acid stripping method, using a commercially available graphite plate with a purity of 99% as an anode, a stainless steel of equal area as a cathode, and a sulfuric acid solution with a mass concentration of 30% as an electrolyte, placed in an electrolytic cell. The temperature of the electrolytic cell is controlled to 75 degrees C, the current density is 10mA/cm2, and the electrolysis lasts for 20 minutes. The surface of the graphite plate is continuously peeled off in the electrolyte to form a suspension, that is, a brown-black graphene oxide dispersion liquid. USE - Graphene sieve photocatalyst for purifying endotoxin in regenerated water. ADVANTAGE - The graphene sieve photocatalyst has great significance to the development of visible light catalysts, and also has good application prospects in the treatment of endotoxins in regenerated water. DETAILED DESCRIPTION - Graphene sieve photocatalyst comprises nitrogen-doped titanium oxide nanotubes are used as the main catalyst and the graphene sieve is used as the co-catalyst. The preparation includes preparing graphene oxide by electrochemical acid stripping method, using a commercially available graphite plate with a purity of 99% as an anode, a stainless steel of equal area as a cathode, and a sulfuric acid solution with a mass concentration of 30% as an electrolyte, placed in an electrolytic cell. The temperature of the electrolytic cell is controlled to 75 degrees C, the current density is 10mA/cm2, and the electrolysis lasts for 20 minutes. The surface of the graphite plate is continuously peeled off in the electrolyte to form a suspension, that is, a brown-black graphene oxide dispersion liquid. The graphene oxide dispersion is purified, centrifuged the obtained graphene oxide dispersion at 5000 rpm for 10 minutes, discarded the precipitate, collected the upper suspension, and centrifuged at 12000 rpm for 30 minutes, and discard it The supernatant, the precipitate is collected, and washed repeatedly with deionized water and ethanol for 5 times to obtain purified pure black graphene oxide particles. The obtained graphene oxide particles and cobalt oxide (Co3O4) nanoparticles are uniformly dispersed in ethylene glycol, ultrasonically dispersed for 30 minutes, and then transferred to an autoclave lined with polytetrafluoroethylene, and control the temperature to 150 degrees C for 24 hours, discarded the ethylene glycol on the upper portion, and then wash with methanol 5 times, after drying, a black-green powder is obtained, which is a graphene sieve. The titanium oxide nanotubes is prepared by electrochemical oxidation, using a mixture of 95 wt.% ethylene glycol, 5 wt.% deionized water, and 0.3% ammonium fluoride as the electrolyte, and titanium plate is the anode, and the stainless steel plate is the cathode. The distance between the plates is maintained at 2.5 cm, and the reaction is carried out at a constant voltage of 40V for 4 hours. The surface of the Ti plate is oxidized to form amorphous titanium oxide nanotubes, which are then immersed in absolute ethanol and washed for 1 hour to remove residual fluoride ions on the surface, and then placed in a muffle furnace and calcined at 450 degrees C for 2 hours to obtain crystalline titanium oxide nanotubes. The titanium oxide nanotubes are placed in a quartz boat and place them in a vacuum tube furnace, continuously passed nitrogen containing 6.5 wt.% ammonia, and controlled the temperature to 500 degrees C for 90 minutes, taken it out after the reaction and cooled naturally to obtain nitrogen-doped titanium oxide nanotubes. The preparation of the graphene sieve catalyst, the graphene sieve is fully mixed with a methanol aqueous solution with a mass concentration of 75%, and after ultrasonic dispersion for 10 minutes, nitrogen-doped titanium oxide nanotubes are added, and the ultrasonic treatment is continued for 24 hours. The nitrogen-doped titanium oxide nanotubes coated with the graphene sieve are separated by an ultrafiltration method, and the graphene sieve catalyst is obtained, after natural drying.