Cellulose Nanofibril-Stabilized Pickering Emulsion and In Situ Polymerization Lead to Hybrid Aerogel for High-Efficiency Solar Steam Generation

A cellulose nanofibril/polylactic acid/polyaniline (CNF/PLA/PANI) hybrid aerogel was developed as an integrated self-floating device for solar steam generation. This hybrid aerogel with tunable structure and morphology was fabricated by lyophilizing CNF stabilized oil-in-water Pickering emulsion gel with PLA/dichloroethane droplets dispersed in an aqueous CNF dispersion, followed by in situ polymerization of aniline. Depending on the extremely low density of 0.03 g/cm3 and porosity of more than 94%, the hybrid aerogel can self-float on the water with good water transport capacity. The optimal CNF/PLA/PANI1-4 hybrid aerogel exhibits 97% light absorption across 300–2500 nm and appealing photothermal conversion capability with surface temperature up to approximately 105 °C under an irradiation of 1 sun. The CNF/PLA/PANI1-4 hybrid aerogel as a steam evaporation device demonstrates an evaporation rate of up to 1.58 kg m–2 h–1 and a steam generation efficiency of 90% at an irradiation of 1 sun. Moreover, the hybrid aerogel shows good cycle durability and structural stability and achieves high purification for saline, industrial wastewater, and organic dye wastewater. The green and sustainable hybrid aerogel demonstrates promising properties and great potential for practical seawater desalination and wastewater treatment.