Synergistic water activation on high-entropy alloy oxides enables ultralow-enthalpy solar desalination
Jinchi Li, Aihao Xu, Hongbing Wang, Bensheng Huang, Liu Yang, Qian Chen, Xinrong Huang, Yingtang Zhou, Xiaoke Li
Abstract
Amidst the escalating global freshwater crisis, solar interfacial evaporation (SIE) stands out as a promising desalination technology, yet its inherent efficiency is fundamentally constrained by the high enthalpy of water vaporization. Herein, we introduce a paradigm-shifting strategy to overcome this limitation by leveraging the unique properties of high-entropy alloy oxides (HEAO). The facile in-situ uniform synthesis of (FeCoNiCuCr) 3 O 4 HEAO nanoparticles on carbon cloth (CC) substrates was achieved via flash Joule heating. Our core innovation lies in the discovery that the HEAO functional layer creates a "hydrophilic-electronic" dual-property surface, which, through the synergistic effect of multi-valence metal sites and oxygen vacancies, actively reconstructs the hydrogen bond network of interfacial water. This manipulation leads to a significant reduction in the apparent evaporation enthalpy to just 1290.9 J g -1 . Consequently, our composite evaporator (CCH) achieves an outstanding evaporation rate of 2.627 kg m -2 h -1 under one sun illumination. Furthermore, combining advanced XPS analysis with density functional theory (DFT) calculations, we provide the atomic and electronic-level evidence for this synergistic mechanism, illuminating the geometric and electronic activation of interfacial water molecules. This work provides an advanced material solution for efficient and stable solar desalination and a transformative theoretical perspective for designing next-generation phase-change materials.