Orientational Bamboo Veneer Evaporator for Enhanced Interfacial Solar Steam Generation

Given the green developments in interfacial solar steam generation (ISSG), a biobased evaporator with excellent photothermal conversion efficiency is urgently needed to address the freshwater shortage. However, it is still challenging that biobased evaporators like wood and bamboo are underutilized due to the capillary actions in different channel directions. Herein, we investigated the channel structural properties of bamboo veneer evaporators for contrast analysis between bamboo transverse sections (BTR) and bamboo tangential sections (BTA). The one-step torrefaction method was used to improve the optical absorption of bamboo lignin in the 200–2500 nm band. Owing to the perpendicular channel design, the BTR evaporator conducting straight energy loss to the bulk water restricts the performance. The BTA evaporator’s parallel channel design with a micronano unit presents better photothermal management (surface temperature could reach 57.1 °C under 1 kW/m2 illumination), leading to efficient evaporation performance (1.425 kg/m2 h). These findings contribute to our cognition of solar-driven water transport and suggest a parallel channel ISSG design to develop efficient biobased ISSG in freshwater produce from seawater or sewage.