Preparation Of Suede-Cotton Fabric-Based Solar Evaporator And Its Photothermal Evaporation Performance Study

To solve the growing problem of freshwater scarcity,desalination using solar interfacial evaporation systems would be an effective method.However,complex processes,poor stability and low solar light utilization have hindered the application of many interfacial solar driven structure evaporators.Therefore,the design of simple,stable and efficient interfacial solar-driven structure evaporators is the focus of solar desalination.Based on this,this thesis takes the design of a simple,stable and light-absorbing layer with high light absorption performance as the starting point to prepare a new and efficient interfacial solar-driven structure evaporator,which provides a new way to solve the problem of freshwater shortage by using solar energy.The main research contents and conclusions of the article are as follows.（1）From the perspective of improving the morphology of the light absorbing layer of evaporator,the article uses the uneven lint on the surface of suede-cotton fabric to cause multiple reflections of light and reduce light transmission to enhance light absorption.A hydrophilic polypyrrole suede-cotton fabric（PPy/S-CF）with broadband light absorption performance（240-1800 nm）was prepared by in situ polymerization using the suede-cotton fabric as the substrate,and the PPy/S-CF was used as the light absorbing layer together with floating polystyrene（PS）foam to form a polypyrrole suede-cotton fabric-based interfacial solar driven structure evaporator.The experimental results show that the evaporator has excellent thermal insulation,hydrophilicity and stability,and has a light absorption rate of 94.5%.Under the light condition of 1 k W/m²,the solar evaporator can achieve a photothermal conversion efficiency of up to 85.21%in simulated seawater,which is 7.36%higher compared with the unbrushed polypyrrole cotton fabric（PPy/CF）.Also this solar evaporator can maintain a high photothermal conversion efficiency in high concentration salt water（20 wt.%）.The solar evaporator was subjected to 15 cycles of experiments under 1 k W/m² of light,and the evaporation efficiency still reached 70.4%,showing good reusability.（2）In this article,from the perspective of improving the light absorption performance of light-absorbing layer absorbing materials,Au³⁺was reduced to gold nanoparticles（Au NPs）using sodium citrate（C₆H₅Na₃O₇）and cellulose hydroxyl functional groups of cotton fabric and grown in situ on PPy/S-CF to prepare gold nano-polypyrrole suede-cotton fabric（Au-PPy/S-CF）,and with floating PS The gold nano-polypyrrole suede-cotton fabric-based interfacial solar-driven structure evaporator was formed together with floating PS foam.The experimental results showed that the solar absorption（240-1800 nm）of Au-PPy/S-CF was as high as 99%,which was 4.5%higher than that of PPy/S-CF.Under the light condition of 1 k W/m²,this solar evaporator can achieve a photothermal conversion efficiency of up to 93.41%in simulated seawater,which is 8.2%higher than that of PPy/S-CF.The solar evaporator can also maintain high photothermal conversion efficiency in high concentration salt water（20 wt.%）.The evaporator was subjected to 15 cycles under 1 k W/m² of light,and the evaporation efficiency still reached 78.77%,showing good reusability.Therefore,the simple,stable and efficient interfacial solar-driven structure evaporator prepared in this thesis helps to alleviate the freshwater shortage problem.