A fast curing assisted spray-coating method to fabricate a robust core–shell structured evaporator with stable solar vapor generation performance

Abstract

Solar driven interfacial vapor generation is considered to be an effective strategy to alleviate the impact of water crisis on human activities. However, great efforts of researchers have been devoted to improving the solar steam generation efficiency, while less attention has been paid to the long-term stability of evaporators. Herein, we proposed a robust core–shell structured evaporator prepared by a simple fast curing assisted spray-coating method. Owing to the inherent superelasticity of melamine–formaldehyde (MF) sponge, the finely designed novel 3D core–shell structure, and the quick curing of branched polyethyleneimine (BPEI) and 5-pentaerythritol pentaacrylate (5Acl) induced special knot shaped photothermal coating, the as-obtained evaporator (CB/MF) performed well in vapor generation with a high water evaporation rate of 2.082 kg m⁻² h⁻¹ under 1 sun illumination, and the evaporation efficiency reached 123.5%, which is comparable to the state-of-the-art artificial solar evaporator. Even in strict application situations, such as long-term recycling testing for 40 h, 500 compression-release cycles (20%, 40% or 60%), sonication for 12 h, or shaking for 30 h, the water evaporation rate of the obtained evaporator remains at a high level of above 2.00 kg m⁻² h⁻¹. Additionally, the evaporator shows effective purification toward high-concentration brine, acid–base solutions, simulated seawater, dye wastewater, and heavy metal wastewater, as well as reliable pure water, providing an outdoor application. With the advantages of a high evaporation rate, stable long-term vapor generation, and effective purification toward various non-potable water sources, we believe that the fabricated core–shell structured CB/MF evaporator is a promising candidate for practical solar steam generation.