Solar vapor generation: Advances in materials engineering and structural design for efficient water evaporation

Global water scarcity driven by climate change and rapid population growth has intensified the need for innovative and sustainable freshwater production strategies. To address this challenge, solar-driven water evaporation, also known as solar-to-steam generation, has emerged as a promising eco-friendly and energy-efficient approach. These systems utilize contaminated sources such as seawater or wastewater and convert sunlight into localized heat to generate purified water through evaporation. Recent advances in photothermal materials including carbon-based structures, semiconductors, polymers and plasmonic composites have significantly improved solar absorption, heat conversion efficiency and evaporation rates. In some cases, solar-to-steam systems have achieved efficiencies approaching unity. However, large-scale production, cost reduction and the lack of standardized evaluation protocols remain major obstacles. This review summarizes recent developments in materials and device architectures for solar vapor generation, identifies key barriers to practical application and outlines future directions. The integration of advanced materials with innovative designs will be critical for realizing scalable, low-cost and sustainable solutions to global water and energy challenges.