TiO₂ nanowire aerogels with interlocking network structure: Achieving ultra-low density and superior strength for thermal insulation

The substantial porosity and adaptability of ceramic aerogels render them promising for various applications. Nonetheless, the conventional compromise among volume density, mechanical properties and thermal stability constrains their applicability in specific contexts. In this study, we have developed and synthesized TiO₂ nanowire aerogels featuring a three-dimensional interlocking network structure. This design imparts the aerogels with exceptional characteristics, including ultra-lightness, high specific strength, and low thermal conductivity. The ceramic aerogels were synthesized through a straightforward hydrothermal reaction process. The resultant TiO₂ nanowire aerogels demonstrate exceptionally low volume densities, reaching values as low as 10 mg/cm³. They exhibit specific strengths up to 11 MPa/(g/cm³) and possess remarkable thermal insulation properties, maintaining mechanical stability across a broad temperature range from −196 to 800 °C. Additionally, they feature an ultra-low thermal conductivity of 0.023 W/(m·K) in air. This study aims to advance the development of innovative designs for high-performance ceramic aerogels, thereby enhancing their applicability across various fields.