High‐Performance Janus CS/MCC Aerogel for Solar‐Driven Seawater Desalination and Organic Pollutant Removal With Salt Resistance

ABSTRACT

Solar‐driven interfacial evaporation has emerged as a sustainable approach to producing clean water. However, conventional evaporators are often limited by low efficiency, severe salt crystallization, and limited functionality, which hinder their practical applications and prospects. To address these challenges, we fabricated a Janus chitosan/microcrystalline cellulose (CS/MCC) aerogel evaporator using a bidirectional regeneration method, followed by hydrophobic modification with 1H,1H,2H,2H‐Perfluorododecyl triethoxysilane (FAS), yielding a CS/MCC‐J aerogel with a hydrophobic surface and a hydrophilic bottom. The evaporator featured a 3D interconnected pore structure with 81.24% porosity. It exhibited an excellent evaporation rate of 2.26 kg m ⁻²  h ⁻¹ , corresponding to an apparent evaporation efficiency of 141%. Under simulated solar irradiation in a 20 wt.% saline solution, the evaporator achieved an evaporation rate of 1.74 kg m ⁻²  h ⁻¹ and an energy efficiency of 96.68%, indicating only a slight decline compared with pure water and demonstrating excellent salt resistance. Additionally, it effectively purified dye‐contaminated wastewater through solar‐driven interfacial evaporation‐assisted separation, as validated using Methylene Blue (MB) and Methyl Red (MR) as model pollutants. These findings provide a novel and economical strategy for solar‐driven seawater desalination and multifunctional water purification.