▎ 摘　　要

NOVELTY - A photochemical reduction nitrogen doped graphene-coated spiral carbon tube three-dimensional composite material preparing method involves mixing 8 g flake graphite with 8 g sodium nitrate, adding 300-450 ml concentrated sulfuric acid with a concentration of 95-99%. 48-80 g potassium permanganate to the mixture is slowly added to obtain a bright yellow suspension. The bright yellow suspension obtained is centrifuged at 500-1000 degrees C for 30-50 minutes to collect precipitate, the precipitate is washed with deionized water repeatedly followed by uniformly coating nickel oxide powder on a ceramic plate, immersing cut foamed nickel in analytically pure hydrochloric acid for 10-20 minutes, so that the oxide on the surface of the foamed nickel is sufficiently etched, putting foamed nickel coated with the electrode material into a quartz tube, and placing 1000w mercury lamp above the quartz tube, and simultaneously complete the nitrogen doping process to obtain nitrogen-doped graphene. USE - Method for preparing photochemical reduction nitrogen doped graphene-coated spiral carbon tube three-dimensional composite material. ADVANTAGE - The method enables graphene-coated spiral carbon tube three-dimensional composite material in convenient, and cost effective manner by realizing the regulation of the nitrogen doping content and the electrical conductivity and mechanical properties of the graphene by the illumination time, intensity and the unique cross-linking action of the mixed spiral carbon tube. DETAILED DESCRIPTION - A photochemical reduction nitrogen doped graphene-coated spiral carbon tube three-dimensional composite material preparing method involves mixing 8 g flake graphite with 8 g sodium nitrate, adding 300-450 ml concentrated sulfuric acid with a concentration of 95-99%. 48-80 g potassium permanganate to the mixture is slowly added, whole system is placed in a low-temperature constant temperature reaction bath, keeping the temperature below zero degrees Celsius, and magnetically stirred for 1-3 hours after the color changes from black to dark green, the reaction temperature is adjusted to 30-40 degrees C for 2-3 hours, 300-400 ml water is added dropwise to the reaction with a dropping funnel, and stirred for 10-30 minutes, continue to add 700-900 ml water and 35-45 ml 25-3 wt.5% aqueous solution of hydrogen peroxide, stirred for 10-30 minutes to obtain a bright yellow suspension. The bright yellow suspension obtained is centrifuged at 500-1000 degrees C for 30-50 minutes to collect the precipitate, the precipitate is washed with deionized water repeatedly until the pH is 7, the quality of the precipitate and the deionized water to obtain graphene oxide. 4000 ml deionized water is added to the graphene oxide, washed in an ultrasonic cleaner for 1-3 hours, the dispersion is finally transferred to a vacuum freeze dryer, and lyophilized the dispersion to obtain fluffy graphene oxide. Nickel oxide catalyst is prepared followed by uniformly coating the nickel oxide powder on a ceramic plate and placing it in a quartz reaction tube, and reducing the nickel oxide at 300-400 degrees C for 1-3 hours in hydrogen atmosphere, and raising the temperature to 400-500 degrees C and change the reaction atmosphere to acetylene, 10-30 sccm flow reaction for 1-2 hours, when cooled to room temperature, taking out the spiral carbon tube, mixing 200 ml analytical pure sulfuric acid and 100 ml analytical pure nitric acid, stirring under reflux at 80-120 degrees C for 24 hours in a water bath to make a hydrophilic oxygen group on the surface of the spiral carbon tube, and the residual nickel catalyst completely removed, after that, centrifuged and lyophilized to obtain a spiral carbon tube powder, preparing graphene oxide dispersion, immersing cut foamed nickel in analytically pure hydrochloric acid for 10-20 minutes, so that the oxide on the surface of the foamed nickel is sufficiently etched, then ultrasonically washed with anhydrous acetone, and the washed foamed nickel is soaked with alcohol, cleaning, immersing foamed nickel in the spiral carbon tubes (HCNTs)/ graphene oxide (GO) mixture so that the HCNTs/GO is sufficiently filled into the pores of the foamed nickel, dried at room temperature, and coating HCNTs/GO mixture, covering the surface of the foamed nickel, drying at room temperature, repeating for 3-5 times to regulate the loading of HCNTs/GO on the foamed nickel, putting foamed nickel coated with the electrode material into a quartz tube, and placing a 1000w mercury lamp above the quartz tube, where spectrum ranges from 200-700 nm and is a monochromatic or white light source, a light source and a quartz tube, distance is 1-30 cm, and the irradiation is carried out for 5-7 minutes in an ammonia atmosphere to carry out reduction and simultaneously complete the nitrogen doping process to obtain nitrogen-doped graphene.