Porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel for efficient visible-light photocatalytic degradation over oxytetracycline

The polyimide is a promising semiconductor photocatalyst. However, its photocatalytic activity is poor because of its small specific surface area, low visible light absorption and easy recombination of photoexcited electron and hole. Herein, porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel with excellent photocatalytic performance is prepared via supercritical fluid drying technology. The material aerogel has large surface area and the structure is porous network. The carbon quantum dots increase the visible light absorption of the polyimide aerogel. The ZnS quantum dots change the VB edge, CB edge and band gap of the polyimide aerogel. Both carbon quantum dots and ZnS quantum dots could improve the charge transfer and facilitate the separation of photoexcited electron and hole. The visible-light photocatalytic performance over oxytetracycline of porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel is increased largely compared to pure polyimide aerogel. The photocatalytic degradation mechanism of the polyimide material aerogel is proposed. ·O 2 − and h + play the key role in the photocatalytic degradation. This work supplies an effective method to prepare visible-light photocatalytic materials. • Porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel was synthesized successfully. • The aerogel possessed large specific surface area and wide visible absorption range. • The aerogel had excellent visible light photocatalytic activity. • The h + and ·O 2 − played important roles to the photocatalytic degradation.