Photothermal materials, structural design and applications of solar-driven interfacial evaporation technology: A review.

Against the backdrop of escalating global freshwater supply-demand imbalance and further implementation of the "dual carbon" strategy, solar-driven interfacial evaporation(SDIE) has become a promising solution forseawater desalination and sewage purification,attributed to its inherent merits including environmental friendliness, low carbon footprint, high energy conversion efficiency and favorable produced-water quality. By constructing localized heating zone at the air-liquid interface through photothermal materials, SDIE greatly reduces heat loss while overcoming the drawbacks of high energy consumption and secondary pollution associated with conventional water treatment techniques. This review systematically summarizes the research background and core mechanisms of SDIE. It analyzes structural features and photothermal conversion behaviors of typical photothermal materials covering carbon substances, semiconductors, metals, polymers, MXenes and biomass-derived materials. Key strategies for boosting evaporator performance are discussed, including porous and biomimetic architectures, water transport tuning, and Janus or 3D structure construction. We further overview technical progresses for seawater desalination, synergistic water purification and disinfection, and coupled applications including zero-liquid-discharge brine treatment and water-electricity cogeneration, together with the industrial application prospects of SDIE systems. Despite advances in material and structural innovation, practical barriers remain, such as high scaling cost, conflicting multi-performance requirements and unsatisfactory outdoor condensation performance. Future work should focus on low-cost composite photothermal materials, multi-scale structural integration and long-term operational stability, to promote SDIE translation from laboratory exploration to real-world engineering and support sustainable global water utilization toward low-carbon goals.