Carbon black and polyetherimide modified ES nonwovens for low-cost and continuous seawater desalination

Solar-powered desalination is considered a promising and sustainable method for producing clean water to alleviate freshwater shortages. However, most solar evaporators have drawbacks such as high costs, complicated processes and lack of durability. Here, we present solar evaporators modified with polyethyleneimine and gallic acid, decorated with carbon black nonwovens, for desalination to produce clean water. The carbon black photothermal nonwovens were produced by treating ES hot air nonwovens with a spray of carbon black solution. Utilizing the light-absorbing heat generation of carbon black and the skin-core structural characteristics of ES(PE/PET) nonwoven, the carbon black is firmly embedded in the PE skin layer of the nonwoven fabric. Subsequently, mussel chemistry inspired the formation of polyethyleneimine and gallic acid coatings on the surface of the carbon black-loaded nonwoven. By combining carbon black with mussel coatings, the photothermal nonwovens demonstrated improved hydrophilicity, excellent photothermal water evaporation performance, and enhanced light conversion efficiency. The modified interfacial evaporator exhibited a high evaporation rate of 1.22 kg m −2 ·h −1 and had high cost-effectiveness of 332.4 g·h −1 ·$ −1 . In addition, reusing, desalination, and outdoor experiments were conducted to showcase the potential of the evaporator for practical desalination. This work demonstrates the significant potential of photothermal ES nonwovens for efficient solar-driven clean water production to tackle global freshwater shortages.