Hierarchical Porous SWCNT Stringed Carbon Polyhedrons and PSS Threaded MOF Bilayer Membrane for Efficient Solar Vapor Generation

Small. 2019 Apr;15(15):e1900354. doi: 10.1002/smll.201900354. Epub 2019 Mar 12.

Abstract

Interfacial solar vapor generation is considered to be an efficient and eco-friendly technology for harvesting solar energy and providing freshwater. However, the efficient and long-term steady evaporation of seawater under 1 sun becomes a critical issue when it comes to practical applications. Based on this issue, a special double-layer structure, which contains a metal-organic-framework-derived hierarchical porous carbon membrane (HPCM) for solar absorption and a polystyrene sulfonate (PSS)@Cu3 (BTC)3 •3H2 O (HKUST-1)/single-walled carbon nanotube (SWCNT) (PHS) membrane for water supply and salt blocking, is designed in this work. The converted heat is utilized efficiently in situ to drive the evaporation of water-trapped HPCM. The PHS membrane with PSS modified channels successfully prevents the deposition of salt. Due to the synergistic combination of the HPCM and PHS membranes, the device exhibits a remarkably high water evaporation rate of 1.38 kg m-2 h-1 and solar-vapor generation efficiency of 90.8% under 1 sun.

Keywords: PSS@HKUST-1/SWCNT composite membrane; anisotropic heat conductivity; efficient solar vapor generation; hierarchical porous carbon membrane; low salt deposition.