Abstract Solar selective absorber coatings (SSACs) with transition metal spinel structure were fabricated with Fe-, Ni- and Co-based nitrate salts by facile sol-gel method and fast spraying process that facilitates large-area coating preparation. By optimizing the doping ratio of three transition metal nitrates, the number of spraying layers and the annealing temperature, the SSAC with solar absorptance of 0.93 and vertical emittance of 0.11 were achieved. The actual and comprehensive heat collection performance was studied by placing the coating samples directly in the sun. The surface temperature of the coating reached 72.8 °C when the outdoor temperature was 33 °C and the sunshine duration was 30 min. The thermal stability of the two-layer Ni0·9Fe0·1Co2Oy coatings was evaluated by continuously heating at 500 °C in the air for 48 h. The solar absorptance remained basically unchanged at 0.93, while the emissivity gradually increased from 0.11 to 0.30. The experimental results also show that the sintering temperature has a great influence on the absorptance of the coating, while the heating duration time has a greater influence on the vertical emittance. It indicates that the Ni0·9Fe0·1Co2Oy coating prepared by fast sol-gel spraying method is a promising SSAC which is easily prepared and applied on complex surface.

中文翻译：

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喷涂法制备钴-镍-铁氧化物涂层的太阳能选择性和空气热稳定性研究

摘要 采用铁基、镍基和钴基硝酸盐，通过简便的溶胶-凝胶法和快速喷涂工艺制备了具有过渡金属尖晶石结构的太阳能选择性吸收涂层（SSACs），有利于大面积涂层的制备。通过优化三种过渡金属硝酸盐的掺杂比例、喷涂层数和退火温度，实现了太阳能吸收率为0.93、垂直发射率为0.11的SSAC。通过将涂层样品直接放在阳光下研究实际和综合的集热性能。当室外温度为33℃，日照时间为30min时，涂层表面温度达到72.8℃。两层Ni0·9Fe0·1Co2Oy涂层的热稳定性通过在空气中500℃下连续加热48小时来评估。太阳吸收率基本保持在0.93不变，而辐射率从0.11逐渐增加到0.30。实验结果还表明，烧结温度对涂层的吸收率有很大影响，而加热持续时间对垂直发射率的影响较大。这表明采用快速溶胶-凝胶喷涂法制备的Ni0·9Fe0·1Co2Oy涂层是一种易于制备和应用于复杂表面的有前途的SSAC。