Graphene Array-Based Anti-fouling Solar Vapour Gap Membrane Distillation with High Energy Efficiency
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Authors
Gong, Biyao
Yang, Huachao
Wu, Shenghao
Xiong, Guoping
Yan, Jianhua
Cen, Kefa
Bo, Zheng
Ostrikov, Kostya
Issue Date
2019
Type
Article
Language
Keywords
Solar energy , Photothermal conversion , Plasma-made nanostructures , Water purification
Alternative Title
Abstract
New concept of solar vapour gap membrane distillation (SVGMD) is based on synergizing of nanochannel-guided water transport, localized heating, and membrane separation from feed solution.First-time introduction of the gap enables long-term stability and non-fouling membrane.SVGMD exhibits a solar-water energy efficiency higher than state-of-the-art solar vapour systems. AbstractPhotothermal membrane distillation (MD) is a promising technology for desalination and water purification. However, solar-thermal conversion suffers from low energy efficiency (a typical solar-water efficiency of similar to 50%), while complex modifications are needed to reduce membrane fouling. Here, we demonstrate a new concept of solar vapour gap membrane distillation (SVGMD) synergistically combining self-guided water transport, localized heating, and separation of membrane from feed solution. A free-standing, multifunctional light absorber based on graphene array is custom-designed to locally heat the thin water layer transporting through graphene nanochannels. The as-generated vapour passes through a gap and condenses, while salt/contaminants are rejected before reaching the membrane. The high solar-water efficiency (73.4% at 1 sun), clean water collection ratio (82.3%), excellent anti-fouling performance, and stable permeate flux in continuous operation over 72h are simultaneously achieved. Meanwhile, SVGMD inherits the advantage of MD in microorganism removal and water collection, enabling the solar-water efficiency 3.5 times higher compared to state-of-the-art solar vapour systems. A scaled system to treat oil/seawater mixtures under natural sunlight is developed with a purified water yield of 92.8kgm(-2)day(-1). Our results can be applied for diverse mixed-phase feeds, leading to the next-generation solar-driven MD technology.
Description
Citation
Gong, B., Yang, H., Wu, S., Xiong, G., Yan, J., Cen, K., … Ostrikov, K. (2019). Graphene Array-Based Anti-fouling Solar Vapour Gap Membrane Distillation with High Energy Efficiency. Nano-Micro Letters, 11(1). doi:10.1007/s40820-019-0281-1
Publisher
License
Creative Commons Attribution 4.0 International
Journal
Volume
Issue
PubMed ID
ISSN
2311-6706