Superhydrophilic polyimide/carbon quantum dots aerogels for superior visible-light photocatalysis and water evaporation

Photothermal evaporation technology can effectively separate pure water from seawater or wastewater, but there are various pollutants in the treatment area. The pollutants not only cause a threat to the environment and biological health, but also block the vapor escape channels inside the absorbent body. Based on this background, this study designs and constructs a dual functional absorber for solar water evaporation and photocatalysis. A superhydrophilic polyimide/carbon quantum dots aerogel (H-PI/CQDs) is prepared. CQDs increase visible light absorption of the aerogels and improve visible-light photocatalytic degradation performance effectively. The photocatalytic degradation mechanism under visible light is proposed. Remarkably, H-PI/CQDs can achieve self-floating and provide continuous and stable water supply during water evaporation. Under the illumination of the sun, the rate of water evaporation is up to 1.59 kg m −2 h −1 . This study successfully achieves water evaporation and photocatalytic degradation, providing a promising method to obtain clean water and prevent environmental pollution.