Dual-functional NiCo2O4 nanofibers/chitosan aerogel for efficient solar evaporation and bacterial removal

Solar-driven interfacial evaporation presents a promising solution to the global water crisis. However, there are challenges in developing low-cost multi-functional evaporators using existing materials. Herein, we developed a double-layer evaporator consisting of a NiCo 2 O 4 nanofibers/chitosan composite aerogel (top layer) and a polyurethane (PU) sponge (bottom layer). The top layer achieves a light absorption rate of 96.42 % across the full spectrum, while the bottom layer effectively reduces heat loss and ensures a continuous water supply. The evaporator achieves a high evaporation rate of 2.23 kg m −2 h −1 under one solar illumination, and has good salt tolerance and excellent stability. In particular, due to the reasonable combination of evaporators, the water yield reached 17.03 kg m −2 in the outdoor experiment with natural light for 9 h. In addition, the antibacterial rate of NiCo 2 O 4 nanofibers/chitosan aerogels against Escherichia coli was as high as 94 %. In this study, a bifunctional composite aerogel with high evaporation efficiency and strong antibacterial activity was proposed, which is expected to be applied in seawater desalination.