Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

Abstract

It is highly desirable to develop a solar-driven interfacial water evaporator with a self-healing ability and high-efficiency water evaporation performance for water distillation and desalination; however, this process is considerably challenging. Herein, by exploiting the advantages of a self-healing hydrophilic polymer, a self-healing hydrophilic porous photothermal (SHPP) membrane was fabricated by curing a mixture of the polymer, carbon black, and NaCl, followed by removal of the NaCl from water. Since the SHPP membrane could serve as a photothermal layer and water transportation channel simultaneously, a solar-driven interfacial evaporator could be fabricated readily by assembling the SHPP membrane with polyethylene foam. We have shown that the SHPP membrane-based evaporator exhibited a water evaporation rate of 1.68 kg m−2 h−1 and an energy efficiency of 97.3%. These values are superior to those obtained using solar-driven interfacial evaporators with self-healing capability. Notably, by hydrogen bonds reformation between the fracture surfaces, the SHPP membrane could regain its structural integrity after breaking, making the SHPP membrane-based evaporator the first to heal entirely and repeatedly from physical damage to sustain its water evaporation capacity. Therefore, the potential of using SHPP membranes to develop stable, long-last ing, and high-efficiency solar-driven interfacial water evaporators is highlighted.