Solar-Driven Interfacial Water Evaporation Using Open-Porous PDMS Embedded with Carbon Nanoparticles

Abstract

Solar-driven evaporation is a promising technology with many potential applications including desalination, power generation, purification, sterilization, and phase separation. Recently, much research has been directed toward increasing solar-driven evaporation efficiencies with photothermal materials that reside at the air−water interface to provide a localized thermal energy source when subjected to solar radiation. In this work, composite foams of carbon nanoparticles (CNPs) and polydimethylsiloxane (PDMS) were fabricated by a facile salt-leaching technique and used as interfacial receivers for solar evaporation. The inclusion of CNPs significantly increases the solar absorptivity of the foams to ∼97% without impacting their inherently low thermal conductivity. Polyvinyl alcohol (PVA) modification was applied to endow the foams with hydrophilicity, thereby enabling continuous water transport to the air−water interface. An enhanced water evaporation rate of 1.26 kg/m 2 •h with a solar-to-evaporation efficiency of 80% was achieved under a relatively low solar input of 850 W/m 2 . With their simple structure and excellent photothermal performance, the PVA-CNP/PDMS foams are promising candidates for solar evaporation applications.

Concentrated Acid‐Induced Dehydration of Fallen Leaves for Efficient, Sustainable, and Self‐Cleaning Solar Steam Generation

“…[1][2][3][4][5][6] The development and design of photothermal conversion materials, which can absorb solar irradiation and convert it into heat, is one of the focuses in this field. [7][8][9] To date, various types of light absorbers, such as metallic nanoparticles, [10][11][12][13] carbonbased materials, [14][15][16] polymers, [17][18][19] and semiconductors [20][21][22] have been demonstrated for efficient solar absorption. [23,24] Among them, carbon-based materials, including exfoliated graphite, graphene, carbon nanotubes, and other carbon materials have attracted extensive attention due to their high-efficiency, chemical stability, and excellent broadband solar absorption.…”

Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

“…4 Recently, solar-driven interfacial water evaporation, which minimizes thermal dissipation and applies most of the heat to the liquid-vapor phase transition by concentrating heat at the water-air interface, has been developed to improve the evaporation efficiency of water. [5][6][7][8][9][10][11][12][13][14][15][16][17] Generally, most of the reported solar-driven interfacial evaporators comprise three parts [18][19] (Scheme 1a1): 1) a photothermal layer with broadband light absorption and high photothermal conversion, 2) a floatable supporting layer with a low thermal conductivity, and 3) a hydrophilic water channel either on the outside or in the middle of the supporting layer that ensures a continuous water supply to the photothermal layer. Although many highefficiency solar-driven interfacial evaporators have been developed, in practical applications, the photothermal layer or water channel can be damaged by scratching or corrosion, thereby deteriorating the water evaporation efficiency (Scheme 1a2).…”

Tailoring of a Piezo‐Photo‐Thermal Solar Evaporator for Simultaneous Steam and Power Generation

“…Interfacial solar heating has been used to develop efficient and advanced solar energy-based steam generation. [7][8][9][10][11][12][13][14] Effective harvesting of the broad spectrum of solar energy and inhibition of heat loss to the environment by diffusion have been used to increase the solar-driven water evaporation efficiency. In addition, the integration of solar evaporators with power generation in recent years shows the potential of using solar-driven water evaporation technology for freshwater and green energy production.…”