Multifunctional Super‐Hydrophilic MXene/Biomass Composite Aerogel Evaporator for Efficient Solar‐Driven Desalination and Wastewater Treatment

Abstract Solar‐driven interfacial evaporation is recognized as a sustainable and effective strategy for desalination to mitigate the freshwater scarcity issue. Nevertheless, the challenges of oil contamination, salt accumulation, and poor long‐term stability of the solar desalination process limit its applications. Herein, a 3D biomass‐based multifunctional solar aerogel evaporator is developed for water production with fabricated chitosan/lignin (CSL) aerogel as the skeleton, encapsulated with carbonized lignin (CL) particles and Ti 3 C 2 Ti X (MXene) nanosheets as light‐absorbing materials. Benefitting from its super‐hydrophilic wettability, interconnected macropore structure, and high broadband light absorption (ca. 95.50%), the prepared CSL‐C@MXene‐20 mg evaporator exhibited a high and stable water evaporation flux of 2.351 kg m −2 h −1 with an energy conversion efficiency of 88.22% under 1 Sun (1 kW m −2 ) illumination. The CSL‐C@MXene‐20 mg evaporator performed excellent salt tolerance and long‐term solar vapor generation in a 3.5 wt.% NaCl solution. Also, its super‐hydrophilicity and oleophobicity resulted in superior salt resistance and anti‐fouling performance in high salinity brine (20 wt.% NaCl) and oily wastewater. This work offers new insight into the manufacture of porous and eco‐friendly biomass‐based photothermal aerogels for advanced solar‐powered seawater desalination and wastewater purification.