Adjusting Channel Size within PVA-Based Hydrogels via Ice Templating for Enhanced Solar Steam Generation

• DOI: 10.1021/acsaem.0c01584
• Publication Date: 2020-08-10T10:25:13Z
• Authors: Chuang Li; Li Fan; Runzhi Zhu; Xin Li; Piao Wen; Xiaowen Zhao; Gang Wang; Jianli Zou; Franklin Kim
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy; 6. Clean water

Solar steam generation has attracted interest in recent years as a clean source for power and water treatment. To achieve high rate of generation, it is important the solar evaporator to not only have photothermal conversion efficiency but also large effective surface area evaporation. Herein, we report use PVA-based composite hydrogels evaporator, which inner channel sizes were adjusted through an ice-templating method. Although PVA been actively pursued promising material influence performance yet well investigated. Up this point, most reported evaporators range several few tens micrometers. In study, narrowed size down submicrometer by suppressing growth ice crystals while freezing hydrogels. Strong capillary force induced narrow channels facilitated transport over long distances. Therefore, even when hydrogel was molded into pillar structure with length centimeters, could be rapidly transported from one end another, allowing evaporation at much increased heights compared larger sizes. The increase led 6.35 kg m–2 h–1 per covered under 1 sun illumination (100 mW cm–2), significantly higher than previously values.