▎ 摘　　要

NOVELTY - Preparing two-dimensional nitrogen-doped porous carbon material comprises (i) preparing 0.025-0.1 g/ml biomass saccharide solution, adding graphene oxide into biomass saccharide solution, adding amino acids, then adding into hot kettle, reacting at 150-180 degrees C for 6-24 hours, washing with deionized water, and drying at 80 degrees C to obtain hydrothermal carbon, and (ii) mixing hydrothermal carbon prepared in step (i) and potassium hydroxide, raising the temperature to 600-800 degrees C at a rate of 1-5 degrees C/minutes for 2-4 hours, washing with deionized water to neutral, and drying at 80 degrees C for 12 hours. USE - The nitrogen-doped porous carbon material is useful for supercapacitor electrode (claimed). ADVANTAGE - The material: has improved electrochemical performance; and is environmentally friendly. DETAILED DESCRIPTION - Preparing two-dimensional nitrogen-doped porous carbon material comprises (i) preparing 0.025-0.1 g/ml biomass saccharide solution, adding graphene oxide into biomass saccharide solution, where the mass ratio between biomass sugar and graphene oxide is 1:0.01-1:0.05, adding amino acids, the mass ratio between biomass sugars and amino acids is 1:0.5-1:2, then adding into hot kettle, reacting at 150-180 degrees C for 6-24 hours, washing with deionized water, and drying at 80 degrees C to obtain hydrothermal carbon, and (ii) mixing hydrothermal carbon prepared in step (i) and potassium hydroxide, the mass ratio between hydrothermal carbon and potassium hydroxide is 1:1-1:4, raising the temperature to 600-800 degrees C at a rate of 1-5 degrees C/minutes for 2-4 hours, washing with deionized water to neutral, and drying at 80 degrees C for 12 hours to obtain final product.