Song Changyuan, Jiang Zhenghao, Gu Xiangyi, Li Hao, Shi Jianwei
School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.
School of Mechanical and Power Engineering, Zhengzhou University, Zhengzhou 450001, China.
J Colloid Interface Sci. 2022 Jun 15;616:709-719. doi: 10.1016/j.jcis.2022.02.075. Epub 2022 Feb 19.
Bilayer solar evaporator combines high photothermal conversion capacity and low heat loss, has become the new darling in interfacial solar steam generation (ISSG). However, the bilayer structure generally achieved by introducing a photothermal coating on the substrate is not conducive to long-term use due to the poor stability of coating. Herein, a fully biomass-based bilayer evaporator is all-in-one designed, using chitosan (CS) as building blocks and CS derived N, S - doped porous carbon (NSPC) as fillers via pre-freezing and freeze-drying. This facile method could realise the quantitative addition of photothermal materials and controllably regulate the structure of the bilayer evaporator, making the structural optimisation readily available. The optimised evaporator exhibits a remarkable evaporation rate of 2.51 kg mh. After 1000 times of pressing, it still maintains at 2.42 kg mh. Additionally, the evaporator displays outstanding long-lasting stability, excellent salt-resistant and degradability. More importantly, a solar desalination device is fabricated for harvesting freshwater outdoor. The daily water production per unit area (4.55 kg) meets the consumption of two adults. This work provides a controllable synthesis strategy of bilayer evaporators for handling global freshwater shortages.
双层太阳能蒸发器兼具高光热转换能力和低热量损失，已成为界面太阳能蒸汽发生（ISSG）领域的新宠。然而，通过在基底上引入光热涂层通常实现的双层结构，由于涂层稳定性差，不利于长期使用。在此，设计了一种全生物质基双层蒸发器，以壳聚糖（CS）为结构单元，通过预冷冻和冷冻干燥，将CS衍生的N、S掺杂多孔碳（NSPC）作为填料。这种简便的方法可以实现光热材料的定量添加，并可控地调节双层蒸发器的结构，使结构优化易于实现。优化后的蒸发器展现出2.51 kg m⁻² h⁻¹的显著蒸发速率。经过1000次按压后，其蒸发速率仍保持在2.42 kg m⁻² h⁻¹。此外，该蒸发器具有出色的长期稳定性、优异的耐盐性和可降解性。更重要的是，制造了一种用于户外收集淡水的太阳能海水淡化装置。单位面积的日产水量（4.55 kg）满足两个成年人的用水量。这项工作为应对全球淡水短缺提供了一种可控的双层蒸发器合成策略。
