Preparation And Properties Of Solar Photothermal Water Evaporation Device Based On Cellulose

The significant problem of the shortage of freshwater resources,increasing water pollution,and the fossil energy crisis is increasingly severe with the rapid growth of the global population and industrialization.Therefore,it’s urgent to develop low-energy,low-cost,and efficient methods to produce clean water.In recent years,solar photothermal water evaporation technology has been widely used in clean water production due to its developable,renewable,and sustainable characteristics.The desired solar photothermal water evaporation device should have the following properties:the hydrophilic structure to facilitate the evaporation surface to transport water,and high light absorption capacity.In this paper,polyaniline and carbonized waste polyphenylene sulfide non-woven fabric（PPS）were used as solar light absorption and photothermal conversion materials,and waste paper,bagasse,and wood cellulose were used as water transport support materials to prepare composite photothermal paper,three-dimensional photothermal gel and photothermal wood for solar photothermal water evaporation.The elements,structure,and optical absorption properties of the photothermal evaporator were characterized by the Scanning electron microscope,Raman spectrometer,X-ray photoelectron spectroscopy,X-ray diffraction,ultraviolet-visible-near infrared spectrometer,and so on.Then the water evaporation capacity,solar-thermal conversion efficiency,and water purification capacity were investigated,the research contents are as follows:（1）Preparation and properties of waste paper-based double layer solar photothermal water evaporation deviceA new type of double-layer photothermal paper is designed based on polyaniline,Aramid nanofibers,and low-cost waste paper.Waste paper is rich in cellulose and has excellent hydrophilic and water transport capacity.The average absorbance of photothermal paper can reach 97.9%during the wavelength coverage of 300-2400 nm.Under a simulated solar illumination,the evaporator with a photothermal evaporation rate of 1.43 kg m^-2 h^-1.The photothermal evaporation rate of the evaporation still remains relatively stable after 10 cycles.The bilayer paper with excellent purification ability for seawater,dye wastewater,and acid-alkali wastewater.（2）Preparation and performance of bagasse-based solar photothermal water evaporation evaporatorThree-dimensional photothermal evaporators were prepared by freeze-drying using carbonization of waste polyphenylene sulfide non-woven fabric and biomass waste bagasse.The water evaporation performance of bagasse evaporators with different heights was investigated.Bagasse has abundant cellulose content and provides excellent water absorption and transport water performance.In the range of 300-2400 nm,the average absorbance of the evaporator can reach 94.73%.Under 1 sun,the 1 cm high evaporator with an evaporation rate of 1.32 kg m^-2 h^-1 and a conversion efficiency of 78%.And the 3 cm high evaporator with an evaporation rate of 1.66 kg m^-2 h^-1 and a conversion efficiency of 92%.The effects of thermal radiation and thermal convection in the environment affect the water evaporation performance of photothermal gels with different heights.（3）Preparation and performance of wood-based 3D solar photothermal water evaporation evaporatorA three-dimensional photothermal wood evaporator was obtained by freeze-drying method from carbonized and wood of waste polyphenylene sulfide nonwoven fabric.Under 1 sun radiation,the water evaporation rate and conversion efficiency of composite photothermal evaporators prepared by carbon black and carbonized waste polyphenylene sulfide non-woven fabric loaded on 1 cm high wood surface were compared.When loaded with carbon black,the evaporation rate is 1.1 kg m^-2 h^-1 and the efficiency is 72.3%.In contrast,the evaporation rate and conversion efficiency of the wood evaporator loaded with carbonized polyphenylene sulfide are relatively higher,which are 1.73 kg m^-2 h^-1 and 89.21%,respectively.Under 1 solar radiation,the carbonized polyphenylene sulfide was loaded on a 3 cm high wood surface with a water evaporation rate of 2.32 kg m^-2 h^-1 and a photothermal conversion efficiency of 132.49%The effect of heat radiation and heat convection in the environment affects the water evaporation performance of the evaporator with different heights.After 10 cycles of testing,the water evaporation performance remained basically unchanged.