Economical Salt-Resistant Superhydrophobic Photothermal Membrane for Highly Efficient and Stable Solar Desalination

Abstract

Recently, solar-driven interfacial water evaporation has shown great potential in desalination. In a practical application, the inevitable pollution and accumulation of salt that make the evaporation efficient cannot be maintained for a long time. Herein, we report a flexible and economical superhydrophobic photothermal membrane composed of polyvinylpyrrolidone (PVP) and carbon nanotubes (CNTs) with a 1H,1H,2H,2H-perfluorodecyltriethoxysilane modification, with a piece of expanded polystyrene used for support and thermal insulation. The prepared floating evaporation device showed a high energy efficiency of 91.1% and an evaporation rate of 1.41 kg m −2 h −1 under one solar irradiation, and neither salt accumulation nor a significant decrease in the evaporation rate of the device was observed after continuous operation for either 40 h or 18 evaporation cycles. In addition, the self-cleaning performance of the membrane enabled its surface to maintain high absorbance for a long time. With the stable and efficient evaporation performance of this device, it provided guidance for the application of efficient and long-term stable solar desalination.

High efficiency solar desalination and dye retention of plasmonic/reduced graphene oxide based copper oxide nanocomposites

“…Signicantly, the evaporation rate of the system in dark was also measured and subtracted from all the measured evaporation rates under illumination. The energy efficiency (h) can be calculated using eqn (2): 18,43 h…”

“…17 Typically, the interfacial evaporation system consists of a bilayer conguration, in which the bottom supporting layer is used to pump water to the top layer to incessantly replenish the water missing as well as reduce heat loss, and the top layer is a photothermal material used to promote the sunlight absorbability and improve the efficiency of solar thermal conversion. 18 Photothermal materials used in the SSG system can efficiently collect solar light and convert it to thermal energy to heat the water at the interface in place of directly heating bulk water to lower heat loss and enhance the efficiency of light-to-vapor conversion. 19,20 The absorption of broadband light and the high wettability of the photothermal layer are the key issues required for high-efficiency solar desalination.…”

“…37 Recently, some semiconductor metal oxides with narrow bandgap as MoO 3 quantum dots, hydrogenated black TiO 2 , and Ti 2 O 3 nanoparticles have also been reported as photothermal materials for solar desalination. 18,38 Although these materials, have a high solar energy conversion efficiency, however, its large-scale application is limited by inexibility, poor stability, low yield, and high cost. 18 Among metal oxide semiconductors, copper oxide (CuO) is a p-type semiconductor with a narrow bandgap of 1.2 eV and high optical absorption coefficient so it is considered as one of the promising selective solar absorbers.…”

“…18,38 Although these materials, have a high solar energy conversion efficiency, however, its large-scale application is limited by inexibility, poor stability, low yield, and high cost. 18 Among metal oxide semiconductors, copper oxide (CuO) is a p-type semiconductor with a narrow bandgap of 1.2 eV and high optical absorption coefficient so it is considered as one of the promising selective solar absorbers. 39 Herein, we report the preparation of a low-cost semiconductor, nanostructured copper oxide (CuO), as one of the viable solar absorbers due to its high solar absorptance, low thermal emittance, and facile and cost-effective synthesis at low temperature.…”

Advanced Signal-Amplification Strategies for Paper-Based Analytical Devices: A Comprehensive Review

“…However, interfacial thermal resistance events occurring after hydrophobic treatment usually lead to remarkably low energy efficiency, limiting the water treatment process. To address this limitation, a carbon nanotube (CNT)-modified superhydrophobic photothermal membrane was recently fabricated on a filter paper substrate for effective water desalination upon solar irradiation [ 104 ]. In particular, the superhydrophobic photothermal membrane was composited from the CNT and polyvinylpyrrolidone (PVP) modified with 1H,1H,2H,2H-perfluorodecyl (CNT@PVP).…”