On January 20, reporters from the Qingdao Institute of Bioenergy and Process Research, Chinese Academy of Sciences, learned from the interview that the membrane separation and catalytic team led by the researcher Jiang Heqing proposed the use of different dimensions Nano-materials composite strategy to achieve the regulation of the surface structure of the photothermal film to improve the light capture efficiency and obtain the desired photothermal evaporation efficiency.This study is expected to promote the application of solar-driven clean fresh water preparation to achieve efficient, green, Sustainable desalination and freshwater protection under emergency conditions.
In recent years, inspired by the natural water cycle, the use of solar-driven water evaporation to obtain clean fresh water has drawn much attention. This technology is expected to be used as an emergency measure in shipwrecks, survival in the wild, or individual survival in underdeveloped areas. Under the conditions of natural evaporation, the utilization of sunlight is lower and the actual evaporation is slower, so researchers in this field have been trying to apply light-heat film materials with good light absorption and photothermal conversion ability to solar driving Evaporation system to improve evaporation efficiency.
This reporter has learned that a large number of previous studies have shown that the controllable microstructure of the rough surface can effectively reduce the diffuse reflectance of light to achieve full absorption of sunlight in the full band is conducive to efficient water evaporation.However, the surface microstructure The construction of the more complex, often require special equipment or means to assist the completion of an increase of film material preparation difficulty and cost.
In response to the above problems, the membrane separation and catalysis team led by researcher Jiang Heqing of Qingdao Energy Research Institute put forward the composite strategy of using nano-materials with different dimensions to realize the regulation of the microstructure on the surface of the photothermal film so as to improve the light trapping efficiency and obtain the ideal photothermal evaporation Efficiency.According to the researchers, they through the two-dimensional graphene and one-dimensional carbon nanotubes compound to achieve a single component of the orderly structure of the disturbance, thereby increasing the surface roughness of the photothermal film through the surface Microstructural optimization reduces the diffuse reflectance in the solar spectral range to less than 4.7% and the surface temperature of the film under illumination to as high as 77 ° C. In addition, this surface microstructure presents a disorderly build-up that increases intra- Porosity, which is conducive to the transport and diffusion of water molecules in the film.Compared with the natural evaporation, the efficiency of the evaporation process based on the nano-composite photothermal film is increased by 190% and the sunlight utilization rate is over 80%.
According to the researchers, the preparation process of such composite films is simple and can be constructed on different porous substrates, expanding the practical application potential under different water systems, not only in simulated water samples containing acid, alkali and organic pollutants To maintain stable performance while accelerating the evaporation of water in saltwater with varying salinities and showing excellent freshwater productivity.The study is expected to promote the use of sunlight-driven clean freshwater production for efficient, green, and sustainable seawater Desalination and fresh water under emergency conditions.Related research results have been published in authoritative academic journals.
