Rational Design of High‐Performance Bilayer Solar Evaporator by Using Waste Polyester‐Derived Porous Carbon‐Coated Wood

Abstract

Wood‐based bilayer solar evaporators, which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation, low heat conduction, renewability, and high light absorbability, hold great promise for water purification. However, previous studies suffer from low evaporation rates and high cost of coatings, and lack a deep understanding how the porous structures of coating layer function. Herein, a novel bilayer solar evaporator is designed through facile surface coating of wood by low‐cost porous carbon from controlled carbonization of polyester waste. The porous carbon bears rich oxygen‐containing groups, well‐controlled micro‐/meso‐/macropores, and high surface areas (1164 m2 g−1). It is proved that porous carbon improves sunlight absorption and promotes the formation of numerous water clusters to reduce water evaporation enthalpy. Owing to these combined features, the bilayer solar evaporator exhibits high evaporation rate (2.38 kg m−2 h−1), excellent long‐term stability, and good salt resistance. More importantly, a large‐scale solar desalination device for outdoor experiments is developed to produce freshwater from seawater. The daily freshwater production amount (3.65 kg m−2) per unit area meets the daily water consumption requirement of one adult. These findings will inspire new paradigms toward developing efficient solar steaming technologies for desalination to address global freshwater shortage.

High-performance salt-resistant solar interfacial evaporation by flexible robust porous carbon/pulp fiber membrane

“…Another challenge of carbon-based absorbers during seawater evaporation is salt crystallization owing to the low hydrophilicity of carbon, which impedes water transport and reduces the evaporation rate. Consequently, carbon materials are often combined with natural hydrophilic matrix (e.g., wood) to construct carbon-based hybrid absorbers with high hydrophilicity [34][35][36][37]. Chao et al [38] prepared a photothermal evaporation system by depositing a layer of carbon dots on the surface of wood, which showed good stability in solar desalination.…”

Development of a novel cellulose foam augmented with candle-soot derived carbon nanoparticles for solar-powered desalination of brackish water

“…When sunlight falls onto a material, an electromagnetic interaction occurs that converts some of the solar energy into other forms such as thermal energy, via a process known as photo-thermal conversion. 12,13 Various photo-thermal advanced materials, such as carbon-based, [14][15][16][17][18][19][20][21][22] plasmonic metal-based, [23][24][25] heat localized materials, 26 metal-organic framework 27 and molybdenum disulfide 28 have been explored. However, these nanomaterials are typically expensive, raise environmental concerns (in terms of the energy required for their production, their use of elements that have limited availability in the earth's crust, or as a result of inherent toxicity), are often biologically non-compatible and may require complicated synthesis processes that restricts their large scale usage.…”

Sunflower-Stalk-Based Solar-Driven Evaporator with a Confined 2D Water Channel and an Enclosed Thermal-Insulating Cellular Structure for Stable and Efficient Steam Generation

“…Moreover, the Ss mainly consists of hydrophilic polysaccharide and lignin, which can activate the water molecules to reduce the vaporization enthalpy by hydrogen bonding. 27,44 The vaporization enthalpy of water in C-Ss is calculated according to the formula E equ = E 0 m 0 /m g , where E 0 refers to the vaporization enthalpy of bare water without evaporators and m 0 and m g , respectively, represent the evaporation rates of water without and with evaporators in the dark. As shown in Figure S5, the vaporization enthalpy of water in C-Ss was much lower than that of bare water, which contributed to the improvement of the water evaporation rate in the dark.…”