Constructing porous polyimide/carbon quantum dots aerogel with efficient photocatalytic property under visible light

Polyimide was widely studied as semiconductor polymer photocatalyst. However, polyimide photocatalyst suffers from small specific surface area, poor visible light absorption and low charge thansfer efficiency. Herein, porous polyimide/carbon quantum dots aerogel was prepared successfully via supercritical CO2 drying method. The carbon quantum dots were obtained by a green hydrothermal method. The carbon quantum dots could be anchored intimately on the polyimide aerogel by π -π stacking interactions. The polyimide/carbon quantum dots aerogel had large specific surface area and porous structure. The carbon quantum dots increased the visible light absorption, adjusted the band structure of the polyimide aerogel and facilitated the generation and separation of photogenerated electron and holes. Thus the photocatalytic property of the polyimide/carbon quantum dots aerogel was increased compared to pure polyimide aerogel. h+ and ·O2– were the main active species to degrade the pollutant. Finally, the mechanism of the photocatalysis under the visible light was proposed.