Hybrid nanofibrous aerogels for all-in-one solar-driven interfacial evaporation

Solar-driven interfacial evaporation is an emerging technology to obtain fresh water using solar energy. However, the complicated system and the corresponding fabrication process severely restrict its large-scale and cost-effective production. Herein, an all-in-one solar-driven interfacial evaporator was fabricated via a hybrid nanofibrous aerogel of aramid nanofibers (ANFs), carbon nanotubes (CNTs), and gold nanoparticles (AuNPs). Assisted by the reprotonation of the ANFs, CNTs are assembled into the nanofibrous network for through-body light-to-heat activity, and AuNPs are set on the surface layer to enhance solar absorption. The aerogel also features low thermal conductivity to suppress heat losses and high capillary action to wick and confine water within the aerogels. Benefitting from the synergistic effect, the aerogel shows a high evaporation rate of 1.53 kg m-2h-1 and an evaporation efficiency of 91.3% under 1 sun irradiation. Simultaneously, the evaporator demonstrates high purification capacity for wastewaters with dyes and heavy metal ions. The integrated structure design and facile fabrication process would make the hybrid nanofibrous aerogel-based all-in-one evaporators promising for cost-effective and large-scale application under ambient solar irradiance.