Patterned nanofibrous membrane via hot-pressing for enhanced solar thermal evaporation

• Published in: Materials chemistry and physics 2023-07, Vol.302, p.127727, Article 127727
• Main Authors: Chang, Meng-Jie, Zhu, Wen-Yao, Wang, Hui, Hui, Qian, Chen, Jia-Liang, Xie, Heng-Xue, Liu, Jun
• Format: Article
• Language: English
• Subjects: Electrospinning; Hot-pressing; Nanofibrous membrane; Solar thermal evaporation
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2023.127727

Composited fibrous membrane has been demonstrated as a type of versatile and efficient photothermal material to produce fresh water by solar thermal desalination, but still suffers from some shortages such as weak mechanical property for reusability and insufficient investigations on the microstructure regulation for higher evaporation performance. In this work, a self-supported carbon black/polyacrylonitrile (CB/PAN) membrane with irregular patterns was facilely manufactured by simple hot-pressing (hp-CB/PAN) for highly efficient solar thermal evaporation. The hot-pressing induces the densification of the nanofibrous membrane and melt adhesion of partial membrane surface, leading to significant increase of the mechanical property and certain improvement of water diffusion, but no detected change of the nanofibrous components. Moreover, the hp-CB/PAN possesses optical absorption of 99.1% over the entire wavelength range of 250–2500 nm. Accordingly, the hp-CB/PAN exhibits an excellent evaporation rate of 1.33 kg m−2 h−1 and a superior photothermal conversion efficiency of 86% under one sun illumination (1000 W m−2), which are much higher than those of 1.27 kg m−2 h−1 and 82.8% for CB/PAN. The obtained hp-CB/PAN can also be utilized for purifying organic polluted solution and repeatedly solar thermal evaporation without attenuation of the evaporation performance. A self-supporting carbon black/polyacrylonitrile membrane with irregular patterns was facilely manufactured by simple hot-pressing for highly efficient solar thermal evaporation. [Display omitted] •Patterned free-standing nanofibrous membrane was constructed by hot-pressing.•Enhanced mechanical and capillary force were achieved after hot-pressing.•Hot-pressed membrane exhibits improved solar evaporation performance.