A bioinspired hollow fiber-based evaporator with hybrid photothermal enhancement for efficient solar steam generation

Abstract

Harvesting sustainable solar energy for interface steam generation is an appealing technological approach to address current water shortages. However, practical implementation has been hindered by suboptimal steam generation rates and significant heat losses. This study proposed a pioneering approach by designing and validating a cost-effective and scalable carbonized kapok fiber-based aerogel (Ni-NCNTs/KF), drawing inspiration from the structural characteristics of penguin feathers. The vertically-aligned Ni-NCNTs array on the surface of the hollow KF achieves exceptional sunlight absorption exceeding 96 %, attributed to a hybrid enhancement mechanism and effective light trapping. Furthermore, the distinctive core–shell architecture of Ni-NCNTs facilitates surface plasmon resonance and fosters efficient electron transfer at the interfaces, resulting in heightened light-to-heat conversion efficiency. The strategic configuration comprising a hydrophobic KF and a hydrophilic Ni-NCNTs effectively regulates water evaporation by spontaneously restricting water transport. Notably, the inherent macroporous nature of kapok fibers (KF) significantly mitigates thermal conductivity, thereby minimizing heat conduction losses. Consequently, Ni-NCNTs/KF exhibits a remarkable water evaporation rate of 3.22 kg m−2h−1 in seawater and an efficiency of 90.5 % under 1 sun. This innovative research not only furnishes a robust design paradigm for the advancement of efficacious photothermal materials but also presents a promising solution for desalination.