Solar vapor generation using 3D printed super-wicking and light-absorbing surfaces

Abstract

Solar vapor generation presents a sustainable method for clean water production, yet its efficiency is often hindered by fixed evaporation interfaces and unexplored influences of wind. Here, we developed a 3D printed surface that is both super-wicking and super-light-absorbing to enhance evaporation rates via the solar-thermal-wind effect. The open micron-sized capillaries over surface enable fluid transport at an extremely fast rate. The contact area between the light - absorbing surface and the bulk water is so minuscule that it facilitates highly efficient interfacial thermal localization while minimizing heat loss. Through its open capillary structure, this surface is capable of maintaining a stable liquid film thickness. Under standard solar illumination conditions and a wind speed of 5 m/s, its evaporation rate can reach up to 9.348 kg/m²/h. The adaptable design to the sun's irradiance allows for optimal solar and wind alignment on a floating platform, enabling optimized evaporation rates. Moreover, this system can effectively purify a wide variety of pollutants, and the water quality after treatment meets the standards of the World Health Organization. This innovative research has advanced the understanding of the impact of the solar-thermal-wind effect on solar evaporation using stable liquid films, and is expected to increase the water evaporation rate in diverse application scenarios.