Solar evaporation and electricity generation of porous carbonaceous membrane prepared by electrospinning and carbonization

Efficient solar evaporation requires photothermal conversion materials with broad band absorption in solar spectrum, high specific area for water evaporation, and sufficient water transport paths. In the current work, porous carbonaceous membrane consists of continuous ultrafine carbon fibers was prepared by electrospinning followed by carbonation and oxidation. The carbonaceous membrane can absorb more than 95% of incident solar energy in the range from 250 to 2500 nm. The carbonaceous membrane has hydrophilic characteristics and continuous channels for sufficient water transport. The ultrafine carbon fibers on the surface of the membrane provide tremendous interfaces for water evaporation. With localized heating design, the carbonaceous membrane delivers a water evaporation rate of 1.33 kg m−2 h−1 and a solar evaporation efficiency of 81.71%. It is also demonstrated that the carbonaceous membrane can recover fresh water from seawater, acid solutions and alkali solutions. Furthermore, the carbonaceous membrane shows the potential of electricity generation driven by solar evaporation.