Engineering metal-phenolic networks anchored cotton fabrics with boosted photothermal properties for sustainable solar desalination

The shortage of fresh water is one of the great challenges facing the world nowadays. Therefore, it has become an important way to develop sustainable and efficient water purification materials. Among, the photothermal water purification has attracted great attention due to its low energy consumption, environmental friendliness and cost-effectiveness. Shortage of fresh water continues to grow around the world, and the recent solar-powered interfacial system has emerged as a sustainable, efficient, and CO2-neutral approach to harvest fresh water. However, the residual salt accumulated on the top surface of solar evaporators accompanied with severely reduced light absorption and steam evaporation efficiency, setting huge obstacles for further industrialization of this technology. Herein, a metal-phenolic network (MPN)-engineered 2D cotton fabric anchored with redox graphene oxide (rGO) is reported, where the MPN coatings afford the engineering of photothermal fabric cottons with high heating efficiency and defined vapor escape. This composite fabric features a high surface temperature of 61 degrees C within 1 min under the irradiation intensity of 1.5 kW m(-2), maintaining the saturation temperature for 20 cycles. Additionally, an extraordinary indoor desalination rate (similar to 1.201 kg m(-2) h(-1)) of concentrated seawater (20 wt%) under simulated sun irradiation without the need for salt crystallization inhibitors is achieved for composite fabrics, attributed to the synergistic effect of MPN and rGO. Given such high affinity and multiple functions of MPNs, this work is expected to facilitate the rational design of solar desalination devices and boost the research translation of MPN materials in broader applications.