UV Irradiation as a Versatile Low-Temperature Strategy for Fabricating Templated Mesoporous Titania Films

Small. 2024 Dec 17:e2409856. doi: 10.1002/smll.202409856. Online ahead of print.

Abstract

Mesoporous titania thin films offer promising applications in sensors, batteries, and solar cells. The traditional soft templating methods rely on high-temperature calcination, which is energy-intensive, incompatible with thermosensitive flexible substrates, and destructive for titania structures. This work demonstrates UV irradiation as a versatile low-temperature and energy-saving alternative for mesoporous crystalline titania fabrication. Grazing incidence wide-angle X-ray scattering analysis reveals a three-stage crystallization process with increasing UV irradiation time supported by photoluminescence data. UV-irradiation-derived samples exhibit crystallinity and crystal size comparable to that of calcination. Integration with block copolymer templated sol-gel synthesis enables the creation of various morphologies, including cylindrical, ordered spherical, and hybrid structures. Characterizations via scanning electron microscopy and grazing incidence small-angle X-ray scattering confirm the homogeneity of morphology in the resulting films. The resulting films maintain similar optical properties despite morphological differences, as demonstrated by photoluminescence and UV-vis measurements. The versatility of UV irradiation extends to different titanium precursors, underscoring it as a flexible and efficient method for mesoporous titania thin film fabrication at low temperatures.

Keywords: block copolymers; low‐temperature synthesis; mesoporous; thin films; titania.