Self-interlocked down Biomass-based carbon fiber aerogel for highly efficient and stable solar steam generation

Carbon aerogels have demonstrated superior properties for generating clean water through sustainable solar steam generation. However, the complex, time-consuming preparation process and the various harmful chemicals involved seriously inhibit the development and applications of carbon aerogels. Herein, down biomass-based carbon fiber aerogel (DCFA) consisting of physically self-interlocked carbon fibers was developed through the simple low-temperature carbonization of natural down cluster (DC) for highly effective solar evaporation. The resulting DCFA has a large amount of carbon (>80 %) and small amounts of sulfur and nitrogen due to its natural disulfide bonds and amino groups, suggesting a unique self-doped carbon property. The low density and high porosity of the DCFA increased the total solar absorbance and suppressed the energy loss during evaporation. As a result, the DCFA possessed solar absorbance of 97.03 %, as well as high evaporation rates of 2.05 and 2.11 kg·m −2 ·h −1 for the treatment of saline water and dye water, respectively, which are higher than most reported results. Moreover, the resulting DCFA could self-float without external assistance, demonstrating that it could be a facile evaporator in practical applications. Additionally, the DCFA retained its evaporation performance after 10 times tests for the evaporation of 3.5 wt% saline water and actual dye wastewater, indicating a long-term capacity for practical employment. These findings suggest that the DCFA could be a feasible alternative for solar-driven evaporation. Simultaneously, the simple, efficient, and chemical-free strategy will inspire subsequent research on the construction of fiber-based functional aerogels and their further development/application in water treatment, thermal insulation, energy generation, energy storage, and other related areas.