Conductive Metal–Organic Framework Nanosheets Constructed Hierarchical Water Transport Biological Channel for High‐Performance Interfacial Seawater Evaporation

• Published in: Advanced materials (Weinheim) Vol. 36; no. 13; pp. e2310795 - n/a
• Main Authors: Qian, Yongqiang, Xue, Guanfeng, Chen, Luzhuo, Xu, Gang, Wang, Guan‐E
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.03.2024
• Subjects: conductive metal–organic framework; Crystallization; Enthalpy; Evaporation rate; Evaporators; Heating; hierarchical structure nanosheet; High temperature effects; Metal-organic frameworks; Nanosheets; Photothermal conversion; Seawater; Steam generation; Substrates; thin film; water evaporation; thin film; conductive metal-organic framework; water evaporation; hierarchical structure nanosheet
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202310795

Solar interfacial water evaporation shows great potential to address the global freshwater scarcity. Water evaporation being inherently energy intensive, Joule‐heating assisted solar evaporation for addressing insufficient vapor under natural conditions is an ideal strategy. However, the simultaneous optimization of low evaporation enthalpy, high photothermal conversion, and excellent Joule‐heating steam generation within a single material remain a rare achievement. Herein, inspired by the biological channel structures, a large‐area film with hierarchical macro/microporous structures is elaborately designed by stacking the nanosheet of a conductive metal–organic framework (MOF), Ni3(HITP)2, on a paper substrate. By combining the above three features in one material, the water evaporation enthalpy reduces from 2455 J g−1 to 1676 J g−1, and the photothermal conversion efficiency increases from 13.75% to 96.25%. Benefiting from the synergistic photothermal and Joule‐heating effects, the evaporation rate achieves 2.60 kg m−2 h−1 under one sun plus input electrical power of 4 W, surpassing the thermodynamic limit and marking the highest reported value in MOF‐based evaporators. Moreover, Ni3(HITP)2‐paper exhibits excellent long‐term stability in simulated seawater, where no salt crystallization and evaporation rate degradation are observed. This design strategy for nanosheet films with hierarchical macro/microporous channels provides inspiration for electronics, biological devices, and energy applications. A large area conductive MOFs nanosheet film with hierarchical macro/microporous structures is fabricated for interfacial seawater evaporation, which effectively reduces the water evaporation enthalpy, enhances the photothermal conversion efficiency, and refreshes the evaporation rate records for MOF‐based evaporators.