Advanced bionic inverted coral solar evaporator: Enhancing sustainable water utilization with efficient and salt-resistant evaporation

Abstract

Interfacial solar-driven steam generation technology shows great potential in addressing desalination and wastewater purification. However, there is a lack of advanced evaporators with high evaporation efficiency and salt tolerance, which is an obstacle to its widespread application. Drawing inspiration from marine coral structures, we develop a bionic inverted coral-type 3D solar evaporator with an array structure using structural engineering design. The microscopically porous vertical channel structure within the overall skeleton enhances the longitudinal reflux of salt ions and water evaporation, while macroscopic gaps in the bionic coral branching facilitate lateral advection–diffusion of salt ions. Numerical simulations confirm that this bionic coral structure design improves the diffusion rate of concentrated brine. Due to the localized surface plasma resonance and the Marangoni effect, the evaporator achieves remarkable water evaporation performance (evaporation rate: 2.72 kg m−2h−1, energy efficiency: 95.8 %) and operates reliably even under 20 % brine concentration (evaporation rate: 2.65 kg m−2h−1) without significant salt crystallization. Furthermore, it exhibits good wettability and robust mechanical properties, capable of withstanding a wide range of temperatures. The efficient and salt-resistant evaporation makes it valuable for applications including desalination, various wastewater treatments, and agricultural irrigation, thereby promoting the sustainable utilization of water resources.