| Fresh water is a valuable resource for human society to survive and develop.With rapid population growth and increasingly serious water pollution problems,mankind is facing an increasingly severe freshwater shortage crisis.In order to meet the demand for fresh water,much effort has been invested in developing advanced desalination technologies,and the scale of desalination facilities worldwide has more than tripled in the past 20 years.However,conventional desalination technologies not only rely on complex and expensive industrial facilities,but also consume large amounts of fossil energy.Solar energy is an inexhaustible green energy source.The efficiency of solar-driven interfacial evaporation technology has been greatly improved by using photothermal materials,modulating micro and nano structures,and changing the force between water and materials.However,in-depth research is still needed on how to improve the long-term stability of interfacial evaporation materials,increase the freshwater collection rate and evaporation behavior under confined environment.Based on this,this thesis focuses on the following work.（1）Cuttlebone@polydopamine/reduced graphene oxide/polypyrrole interfacial evaporation material with high salt tolerance was designed and prepared by combining cuttlefish bone with composite photothermal material.The evaporating material has excellent photothermal properties,and the surface temperature of the evaporating material can quickly rise to～94°C in 1 minute under 1 sunlight intensity.The synergistic effect of the three components of the evaporating material is obvious,and the evaporation rate of 3.5 wt%Na Cl solution is 1.77 kg m-2 h-1 under 1 s sunlight intensity.Under 1 sunlight intensity,salt precipitation will not occur on the Na Cl solution whose concentration is less than 10 wt%.In the continuous evaporation test for 10 days,the average evaporation rate is still very stable.In addition,the evaporated material is very promising for freshwater collection,with a collection rate of 83%at the end of the freshwater collection experiment.（2）By combining the superhydrophobic silicone/melamine composite sponge with thephotothermalmaterial,thesilicone/melaminecomposite sponge@polydopamine/polypyrrole interfacial evaporation material is produced,which has stable photothermal conversion performance,and the surface temperature can rise rapidly to～95.2°C within 1 min under 1 sunlight intensity.Compared with the open system,the evaporation rate in the closed system decreased evidently but the salt resistance was improved.This is owing to lower light intensity,higher relative humidity and temperature in the closed system.The thickness of the hydrophilic layer of the solar evaporator can be precisely regulated by O2-plasma time.The solar evaporator with 2min O2-plasma treatment has the highest evaporation rate of 1.40 kg m-2 h-1 in the closed system.Freshwater collection rates of up to 85%were achieved at the end of the 12 h desalination test with evaporated materials.This paper puts forward a new idea to solve the problem of insufficient stability and salinity resistance of solar energy-driven interface evaporation technology.the experimental material is convenient,the step is simple,the performance of the evaporation material is good,and it has a good application prospect. |
