A self-floating bacterial cellulose supported MoS2@MWCNTs-OH evaporator with efficient salt resistance, antibacterial properties, and selective adsorption

Addressing global freshwater scarcity, solar-driven interfacial evaporation (SDIE) technology has garnered significant attention due to its sustainability and economic advantages. However, challenges including salt accumulation, substantial heat loss, and biofouling still persist when treating the water in nature. Herein, we developed a BM/BPMC Janus aerogel evaporator composed of a hydrophilic top layer and a hydrophobic bottom layer. This aerogel with a self-floating capability, reduced water evaporation enthalpy, enhanced anti-biofouling properties, salt resistance, and efficient thermal localization. Its hydrophilic top layer, fabricated by embedding MoS 2 @MWCNTs-OH within a bacterial cellulose (BC)/polyethyleneimine (PEI) matrix, exhibits synergistic photothermal-antibacterial functionality. The hydrophobic insulating bottom layer, constructed from silanized BC, achieves an ultralow thermal conductivity of 0.036 W·m −1 ·K −1 , enabling highly efficient thermal localization. Vertically aligned microchannels ensure rapid water supply and salt reflux. Synergistically, the positively charged surface of the hydrophilic layer also induces a Donnan effect, significantly enhancing system salt resistance. Furthermore, this cationic evaporator concurrently achieves highly selective adsorption of anionic dyes (>97.8 % removal for MO/CR). Hydroxyl/amino functional groups enriched within the hydrophilic layer markedly reduce evaporation enthalpy by lowering the activation energy of water molecules. Under 1 kW m −2 solar irradiation, the evaporator achieves a water evaporation rate of 2.78 kg·m −2 ·h −1 and an energy conversion efficiency of 113.2 %. This study presents a novel strategy for efficient desalination and synergistic contaminant removal in complex aqueous environments.