环境材料与生态化学研究发展中心知识库

The long-term thermal instability and low solar-thermal conversion efficiency are challenging issues to be addressed for the solar selective absorbing coatings (SSAC). Herein, we describe a novel design for a high performance SSAC based on TiB₂–ZrB₂ composite ceramic. The TiB₂–ZrB₂/Al₂O₃ coatings which deposited on stainless steel (SS) substrates exhibit a high solar-thermal conversion efficiency (η600�C ¼ 82.6%) at 600 �C black body radiation. After annealing at 600 and 700 �C for 100 h in vacuum, the coatings exhibit a higher solarthermal conversion efficiency of η600�C ¼ 84.3%. Unfortunately, the η600�C decreases to 67.5% when the coating is annealed at the 800 �C for 100 h in vacuum, which is put down to oxidation of the absorbing layer, as evidenced by scanning electron microscope (SEM) and Raman spectra. In addition, the color of the coating is changed from dark blue to bright yellow during the thermal stability experiments.