Preparation Of Copper Oxide Based Porous Composites And Photothermal Properties

Energy is an important material basis for the survival and development of human society.With the development of science and technology,the issue of energy use has become an important factor affecting social development.As the largest and most abundant renewable energy among all the energy sources,how to utilize solar energy more efficiently is of vital importance.Direct solar evaporation(DSSG)is a technology that uses solar energy to produce steam from water with temperatures below the boiling point or steam with temperatures at or above the boiling point,offering a very promising solution to the energy and water crisis.The potential applications of solar thermal conversion technology in water purification production,desalination,wastewater treatment,and hydrothermal power have attracted much attention.Although DSSG technology is becoming more and more proficient,there are still some difficulties.For example,metal oxid-based photothermal conversion materials generally have problems of low evaporation performance and high cost.In view of the above problems,this paper innovatively proposed to compound metal oxides with different gel substrates,and realized efficient water evaporation driven by solar energy photothermal under low light intensity by means of process optimization.The main research contents of this subject are as follows:The polyvinyl alcohol/sodium alginate hydrogel compounded with nano-copper oxide was prepared by the cyclic freeze-thaw method,and the nano-scale copper oxide with controllable morphology and good photothermal performance was prepared by the hydrothermal method.The polyvinyl alcohol/sodium alginate hydrogel obtained by freezing and thawing polyvinyl alcohol and sodium alginate in a water bath has good light absorption and mechanical properties,and its evaporation rate can reach 1.66 kg m^-2h^-1under 1 k W m^-2light intensity.Through the tensile test,it is found that its mechanical properties could be enhanced by increasing the amount of copper oxide and the number of freeze-thaw cycles,with the damage rate of the sample was reduced,and its reuse rate was improved.The multifunctional porous PVA/CS/Cu O composited aerogel was prepared by freeze-drying method.Among them,nano copper oxide is used as a light-to-heat conversion material,the PVA/CS/Cu O composited aerogel prepared through optimization of the process combined with the hydrophilicity of chitosan and the water-locking property of polyvinyl alcohol,and with good light absorption,hydrophilicity and mechanical properties,its evaporation rate can reach 2.14 kg m^-2h^-1under 1k W m^-2light intensity.In addition,the use of solar evaporation devices can realize the treatment of simulated seawater and heavy metal wastewater.The treated water meets the drinking water standards.In addition,we have found that it also has a certain purification effect on artificial urine.And because copper oxide itself has a certain bactericidal ability,the aerogel can also kill microorganisms in the lake,so that the biological environment and the fields of material science can be integrated and integrated,and the research field of photothermal materials can be broadened.The chitosan/melamine sponge light-to-heat conversion material containing fly ash copper oxide mixture was prepared by freeze-drying method.Fly ash is a kind of fine solid particles in the ash content of the flue gas produced by the combustion of fuel,mainly containing silicon dioxide(Si O₂),alumina(Al₂O₃)and iron oxide(Fe₂O₃),etc.If a large amount of fly ash is not controlled or processing,it will cause air pollution,and even cause harm to organisms and humans.In this paper,from the perspective of waste recycling,fly ash and copper oxide are uniformly mixed in the chitosan solution,so that the melamine sponge is immersed in the solution and absorbed to a saturated state,and then freeze-dried to obtain super-hydrophilicity and good light.Thermal performance of the composite material,the steam rate can reach 2.19 kg m^-2h^-1under 1 k W m^-2light intensity,and also has a higher evaporation rate under acid-base conditions.The use of solar energy devices can achieve dye removal and simulate seawater and heavy metals and wastewater treatment.