Photo‐Electro‐Thermal Textiles for Scalable, High‐Performance, and Salt‐Resistant Solar‐Driven Desalination

Abstract

Solar‐driven interfacial evaporation is an emerging desalination technology that can potentially relieve the freshwater scarcity issue. To obtain high and continuous evaporation rates for all‐weather, chemically engineered structural materials have been widely explored for simultaneous photothermal and electrothermal conversion. However, many previously reported fabrication processes involve poor integration and considerable energy loss. Herein, a scalable photo‐electro‐thermal textile is proposed to enable high efficiency, long‐term salt rejection, and solar‐driven desalination. Specifically, the photo‐electro‐thermal yarns with a core (commercial electric wire)‐shell (polypyrrole‐decorated Tencel) structure realize the integration of electrothermal and photothermal conversion. The wrapping eccentricity of 1.53 mm and pitch of 3 T cm−1 for the electric wire are rationally regulated to achieve a high surface temperature of over 52 °C at a 3 V DC input. As a result, exceptional and stable evaporation rates of 5.57 kg m−2 h−1 (pure water) and 4.89 kg m−2 h−1 (3.5 wt.% brine) under 1 kW m−2·radiation with a 3 V input voltage are realized. Practical application shows that the textiles can achieve high water collection of over 46 kg m−2 d−1 over the whole day of operation. The constructed photo‐electro‐thermal textile‐based evaporator provides an effective method for commercial and scalable photo‐electro‐thermal conversion to achieve high‐performance and salt‐resistant solar‐driven desalination.