Design and preparation of novel Y2O3-SiO2 composite aerogels for high-temperature thermal insulators

This study successfully prepared a series of novel Y2O3-SiO2 composite aerogels using sol-gel methods. The high-temperature calcined SiO2-poor aerogels exhibit excellent high-temperature thermal stability in terms of shrinkage, porosity, and BET surface area maintenance. SiO2-rich aerogels exhibit more pronounced mesoporous material properties, the BET surface area and pore volume of sample Y2S1 reached 291.04 m2/g and 0.50 cm3/g, an increase of 278.71% and 297.78% over the pure Y2O3 aerogel, respectively. In addition, compared with untreated mullite fiber, the thermal conductivity of the mullite fiber after impregnation with Y2O3-SiO2 composite aerogels decreased by 35.32–45.77% at 300 °C, which is similar to the performance of impregnation with Al2O3-SiO2 composite aerogel (38.31%). Moreover, the Y2O3-SiO2 composite aerogel with a high BET surface area may have potential applications in the field of luminescent materials such as phosphors due to the intrinsic electronic structure of the rare-earth yttrium and its fantastic optical properties.