The lack of crystallinity of the aerogel materials has limited their significance which otherwise have found huge potential in wide variety of applications. In current work, we have developed TiO₂ aerogels by solid-state gelation method using commercially available P25 and ST-01 (commercial Ishihara TiO₂ Powder). The lack of crystallinity in the aerogel framework was resolved via utilizing crystalline TiO₂ nanoparticles and the phase transformation was assessed as a function of phase composition. Via controlled solid-state gelation, surface area retention of 88.7% was achieved whereas the rutile-to-anatase weight fraction (W_R) was considerably enhanced to 0.50. Interestingly, the phase transformation occurred only in P25, which suggests the mixed phase (anatase + rutile) composition as prerequisite for successful phase transformation. Favorably, TiO₂ aerogels imbibe high degree of oxygen vacancies (Vo) responsible for photocatalytic applications. Interestingly, Vo induction is higher for the TiO₂ with anatase phase composition (ST-01) followed by the sample with mixed phase composition (P25). The developed TiO₂ aerogel photocatalysts were employed to dye degradation of Rhodamine B (RhB) and Methylene Blue (MB). The samples attained 94.8% and 96.8% degradation efficiency within 15 min for RhB and MB with nearly 2-fold improvement in the photocatalytic efficiency compared to parent P25 TiO₂ respectively.

https://doi.org/10.1016/j.envres.2023.117409