▎ 摘　　要

NOVELTY - A nitrogen-doped graphene-modified carbon felt preparing method involves soaking the dried carbon felt in an acid solution, immersing in temperature and ultrasonic vibration, washing carbon felt with deionized water, placing the carbon felt into the tubular cavity, pushing the tubular cavity into the heating furnace, sealing, closing the air valve, opening the vacuum pump, nitrogen valve and adjusting gas flow rate, closing the nitrogen valve, turning on methane valve and ammonia valve, adjusting the gas flow rate, heating the tube cavity, adjusting the methane flow rate, opening ammonia gas valve, turning on the radio frequency switch and preparing graphene-modified carbon felt by chemical vapor deposition, turning off radio frequency switch, closing the methane valve, increasing the ammonia flow rate, preparing graphene modified carbon felt by chemical vapor deposition and cooling, closing the ammonia valve and vacuum pump and opening the air valve to obtain the finished product. USE - Method for preparing nitrogen-doped graphene-modified carbon felt for a vanadium redox flow battery (VRB). ADVANTAGE - The method enables preparing nitrogen-doped graphene-modified carbon felt with better conductivity, chemical stability, high specific surface area and excellent electrochemical catalytic performance, in an eco-friendly, simple, easy and cost effective manner, and improving the VRB battery performance. DETAILED DESCRIPTION - A nitrogen-doped graphene-modified carbon felt preparing method involves soaking the dried carbon felt in an acid solution, immersing in temperature and ultrasonic vibration, where the time of soaking the carbon felt in the acid solution is 18-24 hours and the ultrasonic vibration time is 0.5-1.5 hours, washing the carbon felt repeatedly with deionized water, placing the carbon felt into the tubular cavity, pushing the tubular cavity to the central heating zone of the heating furnace, sealing the tubular cavity, closing the air valve, opening the vacuum pump to evacuate until the vacuum of the tubular cavity is as low as 30-50 Pa, opening the high-purity nitrogen valve and adjusting the gas flow rate to 4-8sccm for the flushing of the tubular cavity, after the flushing is completed, closing the nitrogen valve and evacuating until the vacuum is as low as 1-4 mbar, turning on the methane valve and the ammonia valve, adjusting the gas flow rate to 8-12sccm, heating the tube cavity to the first target temperature, the first target temperature is 700 plus minus 10 degrees C, and the heating time is 40-50 minutes, raising the temperature to the first target temperature, the holding time is 1-3 hours, after the end of the heat preservation, raising the temperature to the second target temperature, raising a period of temperature, adjusting the methane flow rate, where, the second target temperature is 750 plus minus 10 degrees C, the temperature rise time is 20-30 minutes, and adjusting the gas flow rate, raising the starting time point is 10-15 minutes from the start of temperature, adjusting the gas flow rate to 2-5 sccm, after raising the temperature to the second target temperature, opening the ammonia gas valve, adjusting the gas flow rate to 2-5 sccm, turning on the radio frequency switch, maintaining the reaction time for 1-30 minutes and preparing the graphene-modified carbon felt by chemical vapor deposition, turning off the radio frequency switch, closing the methane valve, increasing the ammonia flow rate to 6-12sccm, maintaining the reaction time for 2-20 minutes, preparing the graphene modified carbon felt by chemical vapor deposition and cooling with the furnace, after the temperature drops to room temperature, closing the ammonia valve and closing the vacuum pump and opening the air valve to obtain the finished product.