Synthetic Graphene Oxide Leaf for Solar Desalination with Zero Liquid Discharge

Journal Article · Mon Sep 11 00:00:00 EDT 2017 · Environmental Science and Technology

DOI:https://doi.org/10.1021/acs.est.7b03040· OSTI ID:1539046

Finnerty, Casey ^[1]; Zhang, Lei ^[1]; Sedlak, David L.  ^[1]; Nelson, Kara L. ^[1]; Mi, Baoxia  ^[1]

---

1. University of California, Berkeley, CA (United States)

Water vapor generation through sunlight harvesting and heat localization by carbon-based porous thin film materials holds great promise for sustainable, energy-efficient desalination and water treatment. However, the applicability of such materials in a high-salinity environment emphasizing zero-liquid-discharge brine disposal has not been studied. Here this paper reports the characterization and evaporation performance of a nature-inspired synthetic leaf made of graphene oxide (GO) thin film material, which exhibited broadband light absorption and excellent stability in high-salinity water. Under 0.82-sun illumination (825 W/m²), a GO leaf floating on water generated steam at a rate of 1.1 L per m² per hour (LMH) with a light-to-vapor energy conversion efficiency of 54%, while a GO leaf lifted above water in a tree-like configuration generated steam at a rate of 2.0 LMH with an energy efficiency of 78%. The evaporation rate increased with increasing light intensity and decreased with increasing salinity. During a long-term evaporation experiment with a 15 wt % NaCl solution, the GO leaf demonstrated stable performance despite gradual and eventually severe accumulation of salt crystals on the leaf surface. Furthermore, the GO leaf can be easily restored to its pristine condition by simply scraping off salt crystals from its surface and rinsing with water. Therefore, the robust high performance and relatively low fabrication cost of the synthetic GO leaf could potentially unlock a new generation of desalination technology that can be entirely solar-powered and achieve zero liquid discharge.

• Research Organization: Univ. of California, Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); Hellman Family Faculty Fund
• Grant/Contract Number: IA0000018; AC02-05CH11231; CBET-1565452; DGE-1106400
• OSTI ID: 1539046
• Journal Information: Environmental Science and Technology, Vol. 51, Issue 20; ISSN 0013-936X
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
42 ENGINEERING