Economical, Simple‐to‐Prepare, and Salt‐Resistant Evaporator Based on Porous Activated Carbon for Sustainable Solar Evaporation

Abstract

Interfacial solar vapor evaporation is expected to be an emerging technology to solve the scarcity of freshwater due to its sustainability and high efficiency. However, the present application of evaporators is mainly limited by the complex preparation process, expensive cost of raw material, and poor structure. Herein, based on coconut shell activated carbon (CSC) and ultrahigh molecular weight polyethylene (UHMWPE), a cost‐effective and robust CSC/UHMWPE (CSC/PE) evaporator is prepared through sintering in a mold. Benefiting from high light absorptance (≈90%) and excellent thermal localization, the CSC/PE evaporator exhibits an evaporation rate of 1.340 kg m−2 h−1 and an evaporation efficiency of 80.57% in 3.5 wt% brine under 1 sun irradiation. Moreover, by regulating the component ratios, the CSC/PE evaporator achieves superhydrophilicity and proper water transportation rate, and shows long‐term stability with an average evaporation rate of 1.309 kg m−2 h−1 in natural seawater for 10 h. Specifically, the high porosity CSC/PE facilitates the salt resistance in high salinity brine (15 wt%). Importantly, the cost‐effectiveness of CSC/PE is 53.43 g h−1 $−1, which is economical compared to other reported evaporators. Therefore, the economical, simple‐to‐prepare, and durable CSC/PE evaporator has enormous potential in interfacial solar vapor evaporation for freshwater production.