A 3D solar-driven evaporator based on electrospun recycled PET film for efficient seawater desalination

Plastics, especially polyethylene terephthalate (PET) plastic bottles, played an indispensable role in people's lives, yet the plastic crisis was one of the greatest challenges for the planet and humanity today. Processing recycled PET (rPET) into functional materials could achieve both environmental and economic significance. In this work, using rPET and carbon black as raw materials, a low cost 3D seawater evaporator was successfully prepared by electrospinning and folding. By examining the concentration of carbon black (1, 3, 5, 6 wt%) on the photothermal conversion performance of the as-spun films, the optimal concentration 6 wt% was determined. The prepared 6 wt% evaporator showed water evaporation rate about 1.457 kg m−2 h−1 and a conversion efficiency of 93.91% under one solar intensity (1 kW/m2) with good performance stability after 11 cycles for seawater desalination. The desalinated water could meet the WHO and EPA drinking water standards. Meanwhile, the materials cost of the prepared evaporator was about 1.19 USD/m2. Compared to the photothermal conversion efficiency, a photothermal quality factor was calculated, and was 3.81 for the prepared rPET based evaporator, which was higher than most of reported materials. These results suggested the electrospun rPET film might have great potential in seawater desalination and point out a new way to for cleaner reuse of rPET.