Efficient “Core–Shell” Carbon‐Based Solar Evaporator with Honeycomb Structure for Large‐Scale Solar‐Driven Water Purification and Energy Harvesting

Abstract Solar‐driven interfacial water evaporation holds a broad application prospect in the domain of seawater desalination. However, traditional interfacial desalination technology is facing the challenge of large‐scale preparation and desalting performance. Herein, based on the easy processing and low cost advantages of carbon‐based solar‐thermal materials, the study proposes a novel strategy to use the surfactant Pluronic F127 to encapsulate the carbon black to form a size‐stable “core–shell” nanomicelle. Then, the solar‐thermal evaporator cross‐linked by nanomicelle and polyvinyl alcohol is constructed with a surface patterned design inspired by the honeycomb structures, which proved that the evaporator has excellent salt resistance by the Marangoni effect. Furthermore, it can be used to generate electricity and realize the integration of outdoor evaporating water and electricity generation. The solar evaporator can reach an evaporation rate of 2.19 kg m⁻² h⁻¹ under one sunlight irradiation. The area of large‐scale surface patterning can reach 132 cm² (22 cm × 6 cm) and the output voltage under natural light is up to 561 mV. Significantly, the evaporator can maintain persistent water evaporation without surface salt accumulation during the outdoor evaporation of seawater for 10 days. This work provides a valuable perspective for the industrialization of high‐performance solar evaporators.