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

Abstract

AbstractSolar 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.