Study On Solar Photothermal Interfacial Evaporation Performance Of Super Hydrophilic Copper Foam Deposited Graphene Oxide

Solar driven water interface evaporation is one of the applications of solar thermal technology,which has a good application prospect because it fully utilizes solar energy without additional input energy.Solar driven water interface evaporation technology uses photothermal conversion materials to absorb solar radiation energy and transfer heat directly or indirectly to the fluid,so as to achieve the purpose of evaporation.However,current photothermal conversion materials have some problems,such as complex preparation process and high cost.In view of the above problems,this paper uses copper foam and graphene oxide with low cost and wide sources as raw materials to prepare a new solar evaporation interface and study its photothermal conversion performance.The specific research contents are as follows:Using copper foam as raw material,the super hydrophilic copper foam(SHi CF)interface was prepared by simple chemical treatment.In the process of photothermal evaporation,the polystyrene thermal insulation layer can reduce the heat conduction loss of the evaporation interface to the water body,and at the same time,the medical gauze fully ensures the water transmission.For the photothermal evaporation test surface,the evaporation rate of SHi CF evaporation surface under 1k W/m~2 solar illumination is 0.88kg/(m~2h),which is 1.1 times of the evaporation rate of the original copper foam evaporation surface(PCF)without chemical reaction(0.78kg/(m~2h))and 2.8 times of pure water(0.15kg/(m~2h)).The graphene oxide super-hydrophilic copper foams(GO-SHi CF)evaporation interface was prepared by physical deposition on SHi CF.The attachment of graphene oxide enhanced the absorption of sunlight,and the three-dimensional porous structure provided steam escape channel.Under 1k W/m~2solar illumination,GO-SHi CF evaporation rate is 1.1kg/(m~2h),which is 1.2 times of SHi CF evaporation rate(0.9kg/(m~2h)),and 2.8 times of pure water evaporation.Different concentrations of GO-SHi CF were prepared by means of physical deposition.Experimental study found that the evaporation surface with high concentration was blocked by excessive GO in porous nanostructures,which blocked the vapor escape channel,thus limiting the evaporation process.The evaporation interface with low concentration is also poor in photothermal conversion,because the graphene oxide deposited is not thick enough to improve the absorption of sunlight.GO-SHi CF with GO concentration of 1.5mg/m L has strong absorption capacity of sunlight under 1k W/m~2 solar illumination,and can also ensure that the steam escape channel is not blocked.It has the best photothermal conversion efficiency,and the evaporation rate is1.2kg/(m~2h),and the photothermal conversion efficiency is up to 87.4%,which is much higher than other evaporators.In this paper,by preparing the solar evaporation interface of super-hydrophilic copper foams precipitated with graphene oxide,the technical problems of complex preparation process and high cost of photothermal conversion materials are solved,and the photothermal conversion efficiency is improved,which provides the possibility for the practical application of solar evaporation.