Seawater evaporation and purification powered by solar energy are considered as a promising approach to alleviate the global freshwater crisis, and the development of photothermal materials with high efficiency is imminent. In this study, cellulose nanofiber (CNF)/MXene/Ni chain (CMN) aerogels were successfully synthesized by electrostatic force and hydrogen bond interaction force. CMN10 achieved a favorable evaporation rate as high as 1.85 kg m− 2 h− 1 in pure water, and the corresponding evaporation efficiency could be up to 96.04%. Even if it is applied to seawater with multiple interference factors, its evaporation rate can still be 1.81 kg m− 2 h− 1. The superior seawater evaporation activity origins from the promoted separation of photoexcited charges and photothermal conversion by the synergy of Ni chain and MXene, as well as the water transport channel supported by the 3D structure frame of CNF. Most importantly, CMN aerogel can maintain water vapor evaporation rates above 1.73 kg m− 2 h− 1 under extreme conditions such as acidic (pH 2) and alkaline (pH 12) conditions. In addition, various major ions, heavy metals and organic pollutants in seawater can be rejected by CMN10 during desalination, and the rejection rates can reach more than 99.69%, ensuring the purity of water resources after treatment. This work shows the great potential of CMN aerogel as a high-efficiency solar evaporator and low-cost photothermal conversion material. Cellulose nanofiber (CNF)/MXene/Ni chain (CMN) aerogels demonstrated high evaporation of water from sea water.

Electrostatic self-assembly cellulose nanofibersMXenenickel chains for highly stable and efficient seawater evaporation and purification
    Abstract
        Graphical abstract
    1 Introduction
    2 Experimental
        2.1 Sample preparation
            2.1.1 Preparation of MXene
            2.1.2 Preparation of P-Ni chain
            2.1.3 Preparation of CMN aerogel
        2.2 Solar desalination test
    3 Results and discussion
        3.1 Characterization of CMNx
        3.2 Solar-powered water evaporation performance of CMNX aerogels
    4 Conclusion
    Anchor 15
    References

• Shuai Yang(Key Laboratory of Bio‑Based Material Science and Technology, Ministry of Education, College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China)
• Cai Shi(Key Laboratory of Bio‑Based Material Science and Technology, Ministry of Education, College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China)
• Keqi Qu(Key Laboratory of Bio‑Based Material Science and Technology, Ministry of Education, College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China)
• Zhe Sun(Key Laboratory of Bio‑Based Material Science and Technology, Ministry of Education, College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China)
• Handong Li(Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK, College of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China)
• Benbin Xu(Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK)
• Zhanhua Huang(Key Laboratory of Bio‑Based Material Science and Technology, Ministry of Education, College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China)
• Zhanhu Guo(Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK)