Preparation And Photothermal Properties Of Solar Absorption Materials

The market-oriented application of solar-powered interface water evaporation can solve the current energy and environmental pressures,and can also alleviate the current shortage of fresh water resources.Therefore,the study of interfacial water evaporation is very practical.The photothermal conversion material used for solar-driven interface water evaporation should satisfy the following three characteristics:1)structure and composition with high photothermal efficiency;2)micro/nano structure for water transport;3)perfect thermal management system.In order to further study the effect of solar-driven interfacial water evaporation,carbonized cotton wool and CNT/CB composite membranes were prepared by one-step carbonization and vacuum filtration.The interfacial water evaporation of the sample and the power generation performance during the interface water evaporation process were studied.The conclusions are as follows:1.A one-step carbonization of a large amount of readily available absorbent cotton is carried out to prepare a photothermal conversion material for solar-driven interface water evaporation.The coarse structure formed by stacking the fibers of the carbonized cotton facilitates multiple scattering of light and facilitates the transport of water,and it absorption efficiency in the spectral range of 250-2500 nm is as high as 95.5%.When the light intensity is one sun,the carbonized cotton has a water vapor generation rate of1.273 kg/m~2h and an efficiency of 80%.Moreover,the open circuit voltage can be generated in different concentrations of NaCl solution,and the value of the open circuit voltage increases first and then decreases with the increase of the concentration.A voltage of 0.55 V can be produced in a 0.6 M NaCl solution.It can also be used for seawater desalination and dye waste liquid treatment,and has a good treatment effect.2.The CNTs and CB were mixed and then loaded onto a filter paper by vacuum suction filtration,which was used for solar-driven interface water evaporation.The surface roughness of CNT/CB composite membrane increases first and then decreases with the increase of CNT mass fraction.When the CNT mass account is 34%of the total mass,the surface of the composite film is the roughest.Such a rough surface can increase multiple scattering of light and can increase the actual evaporation area of the interface water evaporation.The 34 CNT/CB composite membrane has an absorption rate as high as 97.8%in the wavelength range of 250-2500 nm.When the light intensity is one sun,the rate of water evaporation at the interface of the 34 CNT/CB composite membrane is 1.38 kg/m~2h,and the efficiency is 85%.And when the light intensity is one sun,it can produce an open circuit voltage of 0.058 V in combination with a perfluorosulfonic acid film.It can also be used for seawater desalination,treatment of acid and alkali solutions,dye waste etc.