▎ 摘　　要

NOVELTY - Preparing hollow cobalt tetroxide nano particle/carbon composite material comprises e.g. (1) preparation of polystyrene microsphere-chitosan mixed solution: (1a) placing polystyrene microspheres in a centrifuge tube, adding deionized water, performing ultrasonic dispersion for 10-15 minutes, and centrifuging at a rotation speed of 9000-10000 revolutions/minutes for 20-25 minutes, and discarding supernatant, and (2b) repeating process in (1a) for 2-3 times, adding deionized water for 2-3 hours, adding chitosan solution to ultrasonic solution and stirring for 10-14 hours, the concentration of the chitosan solution is 0.02-0.03 g/ml, the mass ratio of chitosan in the chitosan solution to the polystyrene microspheres is 1:0.8-3, (2) adding graphene oxide aqueous solution to the solution, stirring at room temperature for 4-8 hours, cooling to room temperature naturally, adding cobalt(II) nitrate hexahydrate, and stirring for 10-16 hours at a constant speed. USE - The hollow cobalt tetroxide nano particle/carbon composite material is useful in electrode material of super-capacitor. ADVANTAGE - The material: promotes ion diffusion and electron transport, provides more redox active sites, and energy density of super-capacitor can reach 104 Wh/kg; and has good electrochemical application value. DETAILED DESCRIPTION - Preparing hollow cobalt tetroxide nano particle/carbon composite material comprises (1) preparation of polystyrene microsphere-chitosan mixed solution: (1a) placing polystyrene microspheres in a centrifuge tube, adding deionized water, performing ultrasonic dispersion for 10-15 minutes, and centrifuging at a rotation speed of 9000-10000 revolutions/minutes for 20-25 minutes, and discarding supernatant, and (2b) repeating process in (1a) for 2-3 times, adding deionized water for 2-3 hours, adding chitosan solution to ultrasonic solution and stirring for 10-14 hours, the concentration of the chitosan solution is 0.02-0.03 g/ml, the mass ratio of chitosan in the chitosan solution to the polystyrene microspheres is 1:0.8-3, (2) adding graphene oxide aqueous solution to the solution, stirring at room temperature for 4-8 hours, cooling to room temperature naturally, adding cobalt(II) nitrate hexahydrate, and stirring for 10-16 hours at a constant speed, where the concentration of the graphene oxide aqueous solution is 1-2 mg/ml, the mass ratio of the solute in the graphene oxide aqueous solution to the polystyrene microspheres is 1:8-90, the mass ratio of the cobalt(II) nitrate hexahydrate to polystyrene microspheres is 1:10-90, (3) vacuum drying product obtained at 60-70 degrees C for 24-25 hours, and drying sample to 400-450 degrees C at rate of 1-5 degrees C/minutes under nitrogen atmosphere and maintaining for 1-5 hours, heating to 600-800 degrees C and maintaining for 1-5 hours at heating rate of 1-5 degrees C/minutes under nitrogen atmosphere, and cooling at rate of 5 degrees C/minutes under a nitrogen atmosphere to obtain a black hollow cobalt tetroxide nano particle/carbon composite material.