Fig. 1. The fabrication process of JANA for interfacial steam generation. (a) Photograph of commercial Kevlar threads. (b, c) Photograph and schematic illustration of aramid microfiber suspension and aramid nanofiber sol, respectively. (d) Photograph of aramid gel, whose top surface is sprayed with Au nanoparticle suspension. (e) Photograph of JANA and schematic illustrations depicting the microscopic morphology of the upside PANA and the downside ANA, respectively. (f) Schematic illustration of the steam generation process using JANA.

Fig. 2. Characterizations for morphology, optical absorption, photothermal responses and wettability. (a) Photograph of a large-area JANA cloth with the size of 60 cm × 45 cm. The scale bar stands for 10 cm. (b) SEM images of ANA. The scale bar stands for 1 μm. (c) SEM images of PANA, in which Au nanoparticles are highlighted using yellow fake color. The scale bar stands for 1 μm. (d) Correlation between the differential pore volume and the pore diameter in 1 gram of JANA measured using mercury intrusion method. (e) Absorption spectra of JANA samples with different weight fractions of Au nanoparticles. The blue area represents normalized power of solar irradiating power. (f) Absorption spectra of JANA under sources with different incident angles. (g) Correlation between the temperature variation of JANA and time using switched illumination by a solar simulator with 1-sun output power. Insets are IR images of the JANA at different moments during the photothermal test. (h) Photographs of an ANA and a PANA approaching to a water droplet, respectively.

Fig. 3. Performances of steam generation using JANA. (a) (left) Photograph of the tested sample where JANA floats on a beaker of water. (right) Schematic illustration of the photo-thermo-gravimetry setup to record the real-time temperature and the mass change during the steam generation process. (b, c) (up) Top- and (down) side-view IR images of the beaker during steam generation process with and without the JANA, respectively. (d, e) Mass decrements and evaporation rates of water during the steam generation process with and without JANA, respectively. (f) Photographs of the (up) crystallized and (down) rinsed PANA in saturated NaCl solution, respectively. (g) Mass decrements of saturated NaCl solution during 5 cycles of steam generation processes using a same piece of JANA. (h) Schematic illustration and photograph of a home-made purification setup performing realistic ISSG. Right bottom insets show the accumulation of purified water at 0 h, 3 h, and 6 h, respectively. (i) Correlation between purified water accumulation and time. (j) Normalized contents of water quality indices in purified water and municipal sewage.

Fig. 4. Mechanical and fireproof properties of JANA. (a), (b) and (c) Photographs of JANA pieces which are cut off, rolled up, and elastically stretched, respectively. (d) Tensile stress of JANA. (e) Mass decrements of steam generation processes, in which the JANA is 0 time and 200 times repeatedly stretched, respectively. (f) Photographs of JANA under fire treatments for 0 min, 1 min, 2 min, and 3 min. (g) Mass decrements of steam generation processes, in which the JANA is without and with fire treatment, respectively.