Edge-enhanced ultrafast water evaporation from graphene nanopores
Edge-enhanced ultrafast water evaporation from graphene nanopores
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DOI：
10.1016/j.xcrp.2022.100900
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发表时间：
2022-05
影响因子：
8.9
通讯作者：
Siyang Xiao;Kaixin Meng;Q. Xie;Linxin Zhai;Zhiping Xu;Hao Wang;Chuanhua Duan
中科院分区：
文献类型：
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作者：
Siyang Xiao;Kaixin Meng;Q. Xie;Linxin Zhai;Zhiping Xu;Hao Wang;Chuanhua Duan
石墨烯纳米孔膜是最具潜力的超薄纳米孔膜，由于其高效的热质传递仅受界面蒸发动力学的限制，具有巨大的潜在应用前景。开发这样的膜需要对单孔水平上的蒸发有基本的了解，这在很大程度上还没有被探索。本文报道了直径从24~347 nm的单个/多个圆形石墨烯纳米孔的动力学限制蒸发的实验研究。我们发现，尽管变化很大，但蒸发通量随着纳米孔直径的减小而增加，并且对于直径小于60 nm的纳米孔，最大蒸发通量超过了经典的Hertz-Knudsen公式所预测的动力学上限。我们将这种增强与边缘促进蒸发和气液界面上最小的污染物积累联系在一起。我们进一步发现，这种增强的超快蒸发表现出一种温度不敏感但与直径有关的方式。我们的工作为纳米尺度的蒸发提供了新的见解，并将为开发基于2D纳米材料的膜蒸发器提供启示。
Graphene nanoporous membranes are the ultimate ultrathin nanoporous membranes and have enormous potential applications due to efficient heat and mass transfer that is limited only by interfacial evaporation kinetics. Developing such membranes requires fundamental understanding of evaporation at the single-pore level, which has remained largely unexplored. Herein, we report the experimental study of kinetically limited evaporation from single/multiple circular graphene nanopores with diameters from 24 to 347 nm. We show that, despite a wide variation, the evaporation flux increases as nanopore diameter decreases and that the maximum evaporation flux exceeds the upper kinetic limit predicted by the classical Hertz-Knudsen relation for nanopores with diameters below 60 nm. We associate the enhancement with edge-facilitated evaporation and minimum contaminant accumulation at the liquid-vapor interface. We further find that such enhanced ultrafast evaporation exhibits a temperature-insensitive but diameter-dependent manner. Our work provides new insights into nanoscale evaporation and will shed light on developing 2D nanomaterials-based membrane evaporators.