A series of progress in the research of ultra-high temperature ceramic based solar energy absorbing coating in Lanzhou Institute of Chemical Engineering

High temperature solar absorbing coating is the core material of solar photothermal power generation It also plays an important role in heavy oil mining, desalination, regional heating in winter and coping with haze High temperature solar energy absorbing coating should have high absorptivity, low emissivity and good thermal stability However, the lack of key technologies and core materials of solar photothermal power generation seriously restricts the development of related industries In recent years, the metal dielectric composite coating with high degree of concern is prone to metal oxidation, diffusion and other problems under high temperature conditions, which eventually leads to the degradation of optical properties of the coating How to overcome these shortcomings and prepare solar absorbing coatings with excellent performance has always been a challenge in the field of new materials and energy research (left) preparation diagram of microporous solar energy absorption coating; (right) structural diagram of all ceramic solar energy absorption coating ultra-high temperature ceramics (TIC, WC, HFC, ZrC and tin) have high melting point, high hardness, high thermal conductivity, good oxidation resistance and thermal shock resistance, medium thermal expansion coefficient and potential spectral selection characteristics In recent years, Liu Gang and Dr Gao Xianghu, researchers of Gansu Key Laboratory of clay mineral application (Research and development center of environmental materials and eco Chemistry), Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, have taken the lead in the international research on controllable preparation and structure-activity relationship of ultra-high temperature ceramic based high temperature solar spectral selective absorption coating They cooperated with Wolfgang Theiss, a professor of Aachen University of technology in Germany, and obtained the optical constants of stainless steel, ultra-high temperature ceramics, optical glass, alumina and other materials through optical software simulation, and successfully designed various ultra-high temperature ceramic based solar energy absorbing coatings based on this Based on the results of optical simulation, a series of high temperature solar absorbing coatings, such as SS / TiC / Al 2O 3, SS / tic-y / Al 2O 3, SS / TiC-ZrC / Al 2O 3, SS / tic-wc / Al 2O 3, SS / Al 2O 3, SS / Al 2O 3 (L) - WC / Al 2O 3 (H) - WC / Al 2O 3, SS / TiN / Al 2O 3, were prepared by magnetron sputtering at 300 OC The absorption rate and emissivity of the solar absorbing coating are more than 0.92 and less than 0.12, and they have good thermal stability (more than 600 OC), corrosion resistance and thermal shock resistance Some of the coatings have good long-term thermal stability in the environment of 800 OC vacuum, which is one of the best solar absorbing coatings reported at present (left) chromaticity diagram of color high temperature solar absorbing coating; (right) reflection spectrum diagram of high temperature solar absorbing coating designed by optical simulation Using modern analytical and characterization techniques, the structure-activity relationship of this kind of coating is studied in depth and the mechanism of its optical property attenuation at high temperature is clarified: with the increase of heat treatment temperature, the ratio of I d / I g in the Raman spectrum of the solar absorbing coating of transition metal carbides increases gradually, that is, SP 2C contains With the increase of the amount, the graphitization of the coating surface will be intensified, and the optical properties of the coating will be weakened In order to restrain the increase of SP 2C content in the process of high temperature fitting, SS / TiC ZrC / Al 2O 3 absorption coating was prepared by double target co sputtering The composite ceramic coating has high absorption (more than 0.92), low emissivity (0.11) and high long-term thermal stability (700 OC) In addition, the researchers introduced a small amount of rare earth element yttrium into the membrane system design, and finally prepared the ultra-high temperature ceramic solar energy absorption coating with microporous structure through high temperature (800oC, 5H) vacuum heat treatment The absorption rate is more than 0.90, and the emissivity is less than 0.11, at 800o C has good long-term thermal stability at high temperature, which opens up a new preparation method of microporous ultra-high temperature ceramics At the same time, the researchers also prepared the purple high temperature solar absorption coating (SS / tic-wc / Al 2O 3), and studied its chromaticity, and drew the chromaticity diagram This research work provides a simple and universal new method for the preparation of high-temperature solar energy absorbing coating, enriches and develops the theory of high-temperature solar energy absorbing coating film system, reveals the structure-activity relationship of coating, clarifies the optical attenuation mechanism at high temperature, greatly expands the application of ultra-high temperature ceramics in solar photothermal power generation, and provides controllable high-temperature solar energy absorbing coating The preparation has laid a theoretical foundation, and also has an important application value in the research field of solar absorbing coating at medium and low temperature Relevant research results were published in solar energy materials & solar cells, RSC advanced, optical materials, surface engineering, Journal of materials engineering and performance and other journals At the same time, he applied for a national patent, application No.: 201610418110.92016100418136.3201610418437.6201610418415 X, 201610424296.9201510983832.4201510983817 X Paper link solar energy materials and solar cells 167 (2017) 150-156 solar energy materials and solar cells 164 (2017) 63-69 solar energy materials & solar cells 163 (2017) 91-97 solar energy materials & solar cells 157 (2016) 543-549 solar energy 140 (2016) 199-205 RSC advances 6 (2016) 63867-63873 optical materials 58 (2016) 219-225
Surface Engineering32 (2016) 840-845
Journal of Materials Engineering and Performance 26 (2017) 161-167