Teardrop‐Shaped 3D Solar Evaporator with Multiscale Biomimetic Water‐Supply Structures for Highly Efficient Seawater Desalination

Abstract Increasing the vertical water supply height and effective evaporation area is crucial to designing high‐performance 3D solar evaporators. To achieve the purpose, a teardrop‐shaped 3D evaporator with multiple biomimetic water supply structures is developed. The teardrop‐shaped configuration not only greatly increases the effective evaporation area but also significantly improves the environmental energy utilization efficiency. The cactus‐inspired water supply channels at the bottom greatly increase the vertical water supply capacity, thereby providing a foundation for enlarging the effective evaporation area. Compared with the conical evaporator with the same height and projected area, the teardrop‐shaped evaporator demonstrates 50% of reduction in water supply time and 40% of increase in effective evaporation area. Additionally, the top conical structure enables localized salt crystallization, thereby achieving stable and continuous long‐term desalination and resource recovery without liquid discharge. The optimization of the water supply structure and hydrophilic coating is resulted in the impressive evaporation performance (3.73 kg m −2 h −1 ) and environmental energy efficiency (202.7%). The teardrop‐shaped evaporator demonstrates excellent adaptability and durability in desalination and wastewater treatment, particularly in conditions involving high salinity and strong acids. Environmental and economic assessments reveal the good economic affordability and environmental friendliness of the teardrop‐shaped evaporator.