Enhanced structural and phase stability of titania inverse opals

Low‐Temperature Mullite Formation in Ternary Oxide Coatings Deposited by ALD for High‐Temperature Applications

“…While the Al 2 O 3 inverse opal showed trenches spread all over the surface after heat treatment at 1200 °C (Figure 8a) the mullite-coated opal (Figure 8b) presented a clearly smoother surface without lines. The lines present at the noncoated opal could be related either to grain boundaries formation, as in our previous work with titania inverse opals, [9] or cracks generated due to retraction associated with the alumina α transition combined with the constraint imposed by the substrate, [46] or both. A detailed analysis of the sintering evolution of noncoated alumina inverse opals can be found elsewhere.…”

“…Specifically, the radiation wavelength, which will be reflected, is influenced by the material microstructure assemble, mono-or multistacked, and also the macropore size. [8,9,[13][14][15] This selective behavior in transmission and reflection might pave the way to effective solar thermo photovoltaic energy conversion devices [16,17] and also next-generation thermal barrier coatings.However, retention of the 3D structure for high-temperature applications remains a significant challenge. [10,18] As the length scales in these porous materials are decreased, as higher is the surface area and specific activity.…”

“…When exposed to high temperatures, the material's structure may suffer from detrimental morphological changes, such as extensive grain growth, distortion, and eventually destruction of the total periodically organized structure. [9,10] Therefore, this material needs to not only interact with electromagnetic radiation but also have structural stability and keep its function up to high temperatures (usually higher than 1000 °C). The latter fact could be addressed by coating the substrate material with a ceramic oxide that is stable at high temperatures, either by chemical vapor deposition (CVD) [19] or ALD [20] processes.…”

“…[8,9] Its high ordered porosity of interconnects is attractive for a variety of technological applications, such as porous membranes, catalysts, solid oxide fuel cells, and photonics applications. [10][11][12] The 3D periodic arrangement of pores provides a photonic bandgap to these artificial materials, which prohibits the transmission and hence leads to a reflection of electromagnetic radiation in spectral range which is determined by the materials' properties.…”

High‐temperature stable inverse opal photonic crystals via mullite‐sol‐gel infiltration of direct photonic crystals

“…The development of new high‐temperature stable 3D photonic crystals is currently a challenge, driven by its possible use in different systems, such as reflectors in solar cells, solid oxide fuel cells (SOFCs), photocatalysts, and new‐generation photonic thermal barrier coatings (TBCs) . Particularly, the latter one requires an advanced thermal stability to operate at high temperatures while maintaining specific optical characteristics …”