Gel-loaded Photothermal Material For Solar Photothermal Conversion And Desalination

Solar energy has the characteristics of abundant,clean,efficient,cheap and renewable.Therefore,the use of abundant solar energy to produce clean water by a solar steam generation device is a promising strategy to solve the long-term water and energy shortage.The development of photothermal materials and the application of substrate materials are effective ways to improve the photothermal conversion efficiency(SPCE)of the device.CuS is a semiconductor photothermal material in near-infrared region.It has good photothermal performance owing to the surface plasmon resonance effect under the irradiation of near-infrared light.Ultra-lightweight reduced graphene oxide(r GO)is a promising photothermal material with advantages such as excellent light capture capability,low cost,and easy availability.After treatment,polyacrylamide hydrogel,agar hydrogel and polyvinyl alcohol hydrogel have good support,water transport/evaporation and heat preservation ability,which can improve their SPCE.In this thesis,the hydrogels are used as the base material to prepare three solar steam generation devices with high SPCE and desalination effects,including copper sulfide-macroporous polyacrylamide hydrogel(CuS-m-PAM),self-floating agar-r GO(A-r GO),and CuS-polyvinyl alcohol directional porous material(CuS-PDP).Scanning electron microscope was used to observe the surface morphology of CuS-m-PAM,A-r GO and CuS-PDP.CuS-m-PAM has a rough surface and open macroporous structure,A-r GO surface has uneven wrinkles,and CuS-PDP has vertically arranged pores.These special structures are beneficial to increase light absorption efficiency and quickly replenish the surface with water,so that the solar steam generation devices can maintain long-term efficient operation.X-ray photoelectron spectroscopy,X-ray diffraction spectroscopy,Fourier transform infrared spectroscopy,UV-Vis-NIR spectroscopy and Thermal conductivity meter were used for qualitative analyses of the three solar steam generation devices.In order to further study the SPCE of three solar steam generation devices,the temperature changes of three solar steam generation devices under simulated sunlight were tested and the light-to-heat conversion performance was tested.The effects of heating mode,capacity and structure on the evaporation rate and SPCE were studied.In order to determine the desalination effect of the three solar steam generation devices,the concentrations of various ions in simulated seawater and purified water after testing were tested.The three solar steam generation devices can be comprehensively optimized in light absorption,thermal insulation,water replenishment and steam exhaust,and thus provides a new practical method for maximum utilization of solar steam generation device.