▎ 摘　　要

NOVELTY - Removal of manganese ion in water by nitrogen-modified graphene electrode involves ultrasonically dispersing graphene oxide in deionized water, adding urea, mechanically stirring, heating, soaking the reaction product in distilled water, freeze-drying, dispersing the dried material in a pre-formulated polyvinyl alcohol solution, coating the mixture on a hard paper, freeze-drying to obtain a nitrogen-doped graphene aerogel paper electrode, preparing a manganese ion solution, placing the electrode into the solution, and carrying out adsorption of manganese ion by the electrode. USE - Removal of manganese ion in water by nitrogen-modified graphene electrode (claimed). ADVANTAGE - The method enables simple and rapid removal of manganese ion in water by nitrogen-modified graphene electrode, which has high adsorption efficiency for manganese ion in water. The nitrogen-doped graphene electrode is prepared by simple, convenient and environmentally-friendly method, and has excellent recycling property. DETAILED DESCRIPTION - Removal of manganese ion in water by nitrogen-modified graphene electrode involves ultrasonically dispersing graphene oxide in deionized water for 10-30 minutes, adding urea, mechanically stirring for 15 minutes, adding the mixture to a hydrothermal reactor, placing in a muffle furnace, heating the mixture at 180 degrees C for 12 hours, soaking the reaction product in distilled water for 2-3 days, freeze-drying to obtain a nitrogen-doped graphene aerogel material, mixing the nitrogen-doped graphene aerogel material with a pre-formulated polyvinyl alcohol solution, dispersing to obtain a paste-like dispersion, removing 0.1-0.4 mL dispersion, evenly coating on a hard paper, drying to obtain a nitrogen-doped graphene aerogel paper electrode, preparing manganese ion solution, adding the manganese ion solution into an electric adsorption vessel, placing the paper electrode into the vessel, electrically adsorbing the manganese ion by the paper electrode, monitoring the conductivity by a conductivity meter, removing the voltage on the electrode after adsorption of manganese ion, restoring the conductivity of the solution to near the initial value, and regenerating desorption of the electrode. The electric adsorption of manganese ion is carried out in a three-electrode system. The three-electrode system comprises a paper electrode as the working electrode, a platinum sheet electrode as a counter electrode and a calomel electrode is a reference electrode. The adsorption of the paper electrode is in equilibrium state, when the conductivity is constant.