Plant leaves inspired sunlight-driven purifier for high-efficiency clean water production

• Published in: Nature communications Vol. 10; no. 1; pp. 1512 - 10
• Main Authors: Geng, Hongya, Xu, Qiang, Wu, Mingmao, Ma, Hongyun, Zhang, Panpan, Gao, Tiantian, Qu, Liangti, Ma, Tianbao, Li, Chun
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.04.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 140/133; 140/146; 147/135; 147/3; 639/301/1005/190; 639/301/923/1027; 639/638/541/960; 639/925/927/351; Brines; Composite materials; Efficiency; Graphene; Humanities and Social Sciences; Hydrogels; Hydrophilicity; Isopropylacrylamide; Leaves; Melamine; Molecular dynamics; multidisciplinary; Osmosis; Osmotic pressure; Plants; Poly(N-isopropylacrylamide); Purification; Saline water; Science; Science (multidisciplinary); Sunlight; Transpiration; Water purification; Water treatment
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09535-w

Natural vascular plants leaves rely on differences in osmotic pressure, transpiration and guttation to produce tons of clean water, powered by sunlight. Inspired by this, we report a sunlight-driven purifier for high-efficiency water purification and production. This sunlight-driven purifier is characterized by a negative temperature response poly(N-isopropylacrylamide) hydrogel (PN) anchored onto a superhydrophilic melamine foam skeleton, and a layer of PNIPAm modified graphene (PG) filter membrane coated outside. Molecular dynamics simulation and experimental results show that the superhydrophilicity of the relatively rigid melamine skeleton significantly accelerates the swelling/deswelling rate of the PNPG-F purifier. Under one sun, this rational engineered structure offers a collection of 4.2 kg m −2  h −1 and an ionic rejection of > 99% for a single PNPG-F from brine feed via the cooperation of transpiration and guttation. We envision that such a high-efficiency sunlight driven system could have great potential applications in diverse water treatments. Natural leaves can purify water under sunlight through a combination of osmotic pressure, transpiration, and guttation effects. Here the authors design a composite material mimicking these combined effects, achieving sunlight-driven pure water production from brine with high collection rate.