Woven cattail leaf slips for large-scale, high-efficient and salt-resistant solar water evaporation

Abstract

Solar-driven water evaporation is considered as a potential and economical strategy for freshwater generation, seawater desalination as well as sewage treatment by powerful photothermal conversion. Herein, polypyrrole (PPy) coated woven cattail leaf (PPy@HCL) slips are proposed for solar evaporator. The cattail leaf slips are fabricated on a large scale via plain weaving craft, which demonstrates outstanding water supply capability because of the special honeycomb structure of the cattail leaves. The PPy@HCL slips exhibit small heat conductivity, excellent salt resistance and high solar absorption in UV–vis–NIR range. Consequently, an evaporation rate of ~2.20 kg m−2 h−1 and a corresponding efficiency of 96.6 % under 1 sun irradiation are achieved for the rolled PPy@HCL slips. Moreover, the PPy@HCL slips can be employed to produce freshwater from brine and wastewater. This study shows that the PPy@HCL slips have promising applications as low-cost biomass materials in large-scale and powerful solar evaporators.