An efficient interfacial solar evaporator featuring a hierarchical porous structure entirely derived from waste cotton

Zhenzhen Li; Lingjie Yu; Haodong Ma; Jianglong Chen; Jiaguang Meng; Yongzhen Wang; Yaming Liu; Qingwen Song; Zijing Dong; Menghe Miao; Bo Li; Chao Zhi

doi:10.1016/j.scitotenv.2023.166212

An efficient interfacial solar evaporator featuring a hierarchical porous structure entirely derived from waste cotton

Sci Total Environ. 2023 Dec 10:903:166212. doi: 10.1016/j.scitotenv.2023.166212. Epub 2023 Aug 9.

Authors

Affiliations

¹ Key Laboratory of Functional Textile Material and Product, Ministry of Education, Xi'an Polytechnic University, Xi'an, Shaanxi 710048, China; School of Textile Science and Engineering, Xi'an Polytechnic University, Xi'an, Shaanxi 710048, China.
² Department of Mechanical Engineering, The University of Melbourne, Grattan Street, Parkville, Victoria 3010, Australia.
³ Key Laboratory of Functional Textile Material and Product, Ministry of Education, Xi'an Polytechnic University, Xi'an, Shaanxi 710048, China; School of Textile Science and Engineering, Xi'an Polytechnic University, Xi'an, Shaanxi 710048, China. Electronic address: zhichao@xpu.edu.cn.

PMID: 37567279
DOI: 10.1016/j.scitotenv.2023.166212

Abstract

Interfacial solar evaporators are widely used to purify water. However, photothermal materials commonly constituting most interfacial solar evaporators remain expensive; additionally, the inherent structure of the evaporators limits their performance. Furthermore, the large amount of waste cotton produced by the textile industry is an environmental threat. To address these issues, we propose an interfacial solar evaporator, H-CA-CS, with a hierarchical porous structure. This evaporator is made entirely of waste cotton and uses carbon microspheres (CMS) and cellulose aerogel (CA) as photothermal and substrate materials, respectively. Additionally, its photothermal layer (CS layer) has large pores and a high porosity, which promote light absorption and timely vapor escape. In contrast, the water transport layer (CA layer) has small pores, providing a robust capillary effect for water transport. Combined with the outstanding light absorption properties of CMS, H-CA-CS exhibited superior overall performance. We found that H-CA-CS has an excellent evaporation rate (1.68 kg m^-2 h^-1) and an efficiency of 90.6 % under one solar illumination (1 kW m^-2), which are superior to those of many waste-based solar evaporators. Moreover, H-CA-CS maintained a mean evaporation rate of 1.61 kg m^-2 h^-1, ensuring sustainable evaporation performance under long-term scenarios. Additionally, H-CA-CS can be used to purify seawater and various types of wastewater with removal efficiencies exceeding 99 %. In conclusion, this study proposes a method for efficiently using waste cotton to purify water and provides novel ideas for the high-value use of other waste fibers to further mitigate ongoing environmental degradation.

Keywords: Cellulose aerogel; Composite materials; Desalination; Recycling; Wastewater treatment.