Advanced strategies in solar interfacial desalination: Enhancing water productivity and salt resistance

Solar-driven interfacial desalination is an appealing and sustainable technology designed to address global energy and water crises. It can be categorized into forward, reverse, and non-contact desalination based on operating modes. First, we compare and analyze the advantages and disadvantages of these three modes, as well as the key factors affecting their performance. We then review advanced designs for forward interfacial desalination, focusing on material fabrication and optimizing macroscopic mass transfer. Next, we present improvements in single-stage and multi-stage systems for reverse interfacial desalination. Finally, we summarize the performance of contactless interfacial evaporators, both with and without hydrophilic capillary wicks. On the other hand, salt accumulation is the primary challenge to the stable operation of interfacial evaporators. This review discusses current strategies for mitigating salt accumulation, including directional salt crystallization, flowing liquid salt removal, convection and diffusion reflux, and Janus bilayer wettability-based salt resistance. Our analysis reveals specific coupling relationships between salt resistance mechanisms and capillary water transport methods, suggesting these pairings can be adapted to diverse operational scenarios. Furthermore, we explore broader applications of interfacial desalination, including crop irrigation, water and power cogeneration, and sterilization. This review provides a timely and comprehensive analysis and comparison of interfacial desalination systems, aiming to improve both water productivity and salt resistance. © 2024 Elsevier B.V.