Two-dimensional layered MBene membrane towards sustainable freshwater production from solar interfacial evaporation

Solar-driven interfacial steam generation (SISG) is a promising cutting-edge technology for addressing challenges related to water scarcity and environmental issues. Solar-to-heat conversion is essential for this technology and highly relies on photothermal materials. Herein, we present a new class of two-dimensional (2D) layered photothermal materials, namely 2D transition metal boride MBene, to integrate thermally insulated nylon membrane to create SISG evaporator for solar steam generation. The MBene membrane gains broadband light absorption, effective heat localization and rapid water transport, which exhibits excellent solar steam generation performance with a high evaporation rate of 1.59 kg m-2h−1 and efficiency as high as 96.66 % under one-sun irradiation. Significantly, the MBene membrane displays favorable robustness and flexible applications in steaming various contaminated wastewater sources (e.g. organic dyes, antibiotics, oil–water emulsions, heavy metal and acidic/alkaline solutions) at high rejection efficiency and outstanding durability. Meanwhile, the sustainable production of high-quality freshwater through solar desalination of seawater and brine solutions can be also achieved over this SISG system. The present study demonstrates a new photothermal conversion capability of MBene-based materials and its great potential in SISG applications.