Hydrophobic TiO2–SiO2 composite aerogels synthesized via in situ epoxy-ring opening polymerization and sol-gel process for enhanced degradation activity

• Published in: Ceramics international 2020-03, Vol.46 (4), p.4939-4946
• Main Authors: Parale, Vinayak G., Kim, Taehee, Lee, Kyu-Yeon, Phadtare, Varsha D., Dhavale, Rushikesh P., Jung, Hae-Noo-Ree, Park, Hyung-Ho
• Format: Article
• Language: English
• Subjects: Anatase; Photocatalysis; Sol-gel process; Supercritical drying; TiO2-SiO2 composite aerogel
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2019.10.231

TiO2–SiO2 composite aerogels composed of an organic-inorganic molecular network were synthesized via an epoxy-ring opening polymerization and sol-gel procedure followed by supercritical drying. The ring opening polymerization and sol-gel reaction were performed using epoxy-functionalized (3-glycidyloxypropyl)trimethoxysilane and amine-functionalized 3-aminopropyltriethoxysilane. This process was followed by hydrolysis and condensation of methyltrimethoxysilane (MTMS) and titanium butoxide (TBO) in the presence of oxalic acid as a catalyst. The results revealed that the TBO:MTMS molar ratio plays an important role in enhancing the crystallinity, porosity, and surface area of the prepared composite aerogels. Anatase titania was obtained with the as-prepared supercritical dried aerogels and the photocatalytic performance of the aerogels was evaluated via the degradation of a methylene blue textile dye under ultraviolet-light irradiation. The results demonstrated that the TiO2–SiO2 composite aerogel catalyst can yield 87% degradation with a high reaction constant (k = 1.18 × 10−1 min−1). This approach provides a new method of synthesizing TiO2–SiO2 composite aerogel photocatalysts.