High salt-resistant and robust MXene@oleylamine/PET composite nonwoven for efficient and long-term solar desalination

2D transition metal carbides/nitrides/carbonitrides (MXenes) have received extensive attention in solar seawater desalination due to their hydrophilicity, 100 % photothermal conversion efficiency, and efficient light-trapping by enhancing localized surface plasmon resonance (LSPR). Nevertheless, the easily oxidizable characteristics of MXenes, along with salt accumulation and structural weakness impede their practical application in solar-driven interfacial evaporators. Herein, a hydrophobic MXene@oleylamine/polyethylene terephthalate (MXene@OAm/PET) nonwoven with long-term operational stability is fabricated via firmly chemical cross-linking between oleylamine (OAm) modified MXene (MXene@OAm) and NH 2 -PEG-COOH treated PET nonwoven (PEG-PET). The MXene@OAm endows excellent oxidation resistance and hydrophobicity. The prepared MXene@OAm/PET nonwoven which exhibits broad-spectrum solar absorption and high efficiency, can achieve an average evaporation rate in 3.5 wt% NaCl solution at 1.26 kg·m −2 ·h −1 and no seeable salt deposition during 15 irradiation cycles for 8 h a day indicates its superior salt resistance and long-term stability. Most importantly, after being soaked in 3.5 wt% NaCl solution for 40 days, the evaporation rate of MXene@OAm/PET nonwoven still remains stable at around 1.22 kg·m −2 ·h −1 , indicating the significant potential of this prepared nonwoven for long-term seawater desalination and its suitability for industrial applications. Even in industrial wastewater, the evaporation rate can reach 1.27 kg·m −2 ·h −1 . This work demonstrates a successful strategy for achieving high efficiency, stability, and superior salt resistance, which can be potentially utilized in seawater desalination and wastewater treatment.