环境材料与生态化学研究发展中心知识库

Traditional metal-dielectric composite coating has found important application in spectrally selective solar absorbers. However, fine metal particles can easily diffuse, congregate, or be oxidized at high temperature, which causes deterioration in the optical properties. In this work, we report a new spectrally selective solar absorber coating, composed of low Al₂O₃ ceramic volume fraction (Al₂O₃(L)-WC) layer, high Al₂O₃ ceramic volume fraction (Al₂O₃(H)-WC layer) and Al₂O₃ antireflection layer. The features of our work are: 1) compared with the metal-dielectric composites concept, Al₂O₃-WC nanocomposite ceramic successfully achieves the all-ceramic concept, which exhibits a high solar absorptance of 0.94 and a low thermal emittance of 0.08, 2) Al₂O₃ and WC act as filler material and host material, respectively, which are different from traditional concept, 3) Al₂O₃-WC nanocomposite ceramic solar absorber coating exhibits good thermal stability at 600 °C. In addition, the solar absorber coating is successfully modelled by a commercial optical simulation programme, the result of which agrees with the experimental results.