Gradient engineering in interfacial evaporation for water, energy, and minerals harvesting

Abstract

The decarbonization of energy systems underscores the critical role of solar-driven interfacial evaporation (SDIE) for clean energy production. By leveraging solar energy to induce water evaporation, SDIE systems generate ion concentration, salinity, and temperature gradients that enable the co-production of water, green electricity, and valuable minerals. However, the performance and sustainability of SDIE co-production systems is restricted by a limited understanding of the underlying mechanisms that drive the energy and mass gradients formation. In this perspective, we first outline the typical SDIE-based water-energy-minerals co-production (SWEM) systems. Next, based on material and system optimization, we propose rational strategies to enhance gradient formation through the regulation of energy and mass transfer processes, with the aim of strengthening the energy and resources output of SWEM. We also explore hybrid methodologies integrating multiple physical fields using gradient engineering, to achieve synergistic enhancements while mitigating gradient conflicts. Finally, we identify the current challenges and outline future directions to develop next-generation SWEMs, aiming to enhancing the sustainability and resilience of sustainable energy supply chains.