Study On Preparation And Properties Of Graphene Composite Photothermal Conversion Materials

At present,there are many places especially deserts and island areas in the world where is lacking fresh water.Therefore,many countries have started to attach to development of desalination.The application of solar energy as a clean energy to the field of desalination has attracted more and more attention.In recent years,such as nano-gold particles,carbon-based composites(carbon nanotubes,graphene),including discarded biomass materials have been paid to localize evaporation of interfaces.using the light-to-heat conversion properties of these materials for gas-liquid interface evaporation which has effectively improved the conversion efficiency.In this paper,graphene is used as the light-to-heat conversion material,and a graphene composite membrane is prepared by deposition methods and electrostatic spinning experiments.The seawater desalination properties of the material were studied.The following research results have been obtained.An advanced graphene-load Non-woven material has been made by the deposition method.The light absorption performance of the composite film is analyzed by simulating the radiation from the 980nm laser light source.The results are as follows:the 980nm laser source is used to radiate at the environment temperature of 300K.The water evaporation loss is analyzed by electronic balance connection computer software.The results show that the evaporation rate is 2 times higher than the blank control nonwoven fabric film.Sunlight simulation is performed outdoors,the closed hybrid system is under 6h of solar radiation,the solar is used to analyze by densitometer.The results show that the average solar density is about 726 kw/m~2.The composite material of one square meter of graphene nonwoven fabric can make 2.35 liters of water to evaporate into water vapor.Evaporation efficiency reached 50.4%.The modified Hummers method was used to prepare graphene GO dispersion,and the PVA-GO composite membrane was prepared by electrospinning.The results show that the amount of evaporated water of PVA-GO was increased with the increase of GO mass concentration.When GO mass concentration reached 7%the PVA-GO composite membrane was electrospinning into a fibrous network structure,which has a good photothermal conversion performance.The surface characteristics of the PVA-GO composite membrane were analyzed by SEM.The PVA membrane without added GO was a filamentous structure with a smooth surface and uniform fiber diameter distribution.When the PVA was filled with7%GO,the fiber structure was reticular and part of the GO uniformly wrapped the fiber filament.The Evaporation rate of the PVA-GO composite membrane was 0.81 kg/(m~2?h)at the same conditions when irradiated with 980nm infrared laser which was about two times that of the polyvinyl alcohol membrane.Evaporation efficiency could reach 51%.