Hybrid solar-driven interfacial evaporation systems for water-energy nexus: recent advances in freshwater and energy sustainability

Facing global freshwater scarcity and an ongoing energy crisis, solar-driven interfacial evaporation (SDIE) technology, based on the thermal localization principle, can achieve over 90% solar energy utilization efficiency. This review systematically summarizes the evolution of SDIE from efficient freshwater production to a multifunctional platform for synergistic water-energy-resource production. Research focus has expanded from fundamental optimizations such as photothermal materials, water transport, and thermal management to multi-energy-level synergistic strategies (system achieves cascaded utilization and recovery by integrating different forms of energy), including environmental energy harvesting and condensation latent heat recovery. These advances have significantly improved system performance and application boundaries. Notably, SDIE has been successfully coupled with various power generation technologies. These include thermoelectric, salinity gradient, and hydrovoltaic technologies. This coupling demonstrates the potential for the co-production of freshwater and electricity using only solar energy as the input. Furthermore, its applications have expanded into emerging fields. These fields include resource recovery, such as extraction of lithium/uranium, wastewater purification, and environmental remediation. Nevertheless, challenges persist regarding the material stability, system integration, scalability, and economic feasibility of SDIE. Orderly advancement of the following research areas can promote SDIE. It can move from laboratory research to large-scale application. The first area is deepening the understanding of multiscale mass and heat transfer mechanisms. The second is developing low-cost smart materials. The third is constructing integrated, synergistic systems. The fourth is advancing pilot-scale validation. This will provide sustainable solutions to address the interconnected challenges of water, energy, and the environment.