Enhanced photocatalytic performance of mesoporous TiO2 coated SBA-15 nanocomposites fabricated through a novel approach: supercritical deposition aided by liquid-crystal template

• Highly uniform mesoporous TiO2 nanopartices were coated SBA-15.
• MT showed smaller crystallite size, higher hydroxyl content and surface area.
• MT/SBA-15 show enhanced photocatalytic activity and high reused activity.
• The optimum MT loading rate and calcination temperature were obtained to be 15% and 400 °C, respectively.
• Photocatalytic behaviors are discussed in terms of the Langmuir–Hinshelwood model.

Mesoporous TiO2 coated SBA-15 (MT@S) nanocomposites were fabricated through supercritical CO2 deposition aided by liquid-crystal template. The as-prepared samples were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy and so on. The results reveal that MT uniformly deposited onto silica with titania incorporated in SBA-15 channels, showed smaller crystallite size, higher hydroxyl content and surface area than nonporous TiO2 coated SBA-15 (NT@S) obtained by a similar route without template. With TiO2 loading ratio of 15 wt% and calcination temperature of 400 °C, 15%MT@S-400 showed the enhanced degradation efficiency for azo dyes (methylene blue, methyl orange, and rhodamine B) and phenol in comparsion with 15%NT@S-400, due to those improved textural and physicochemical properties. Meanwhile, the reused MT@S also showed high photoactivity. Additionally, the effects of MT content and calcination temperature have been examined as operational parameters. Photocatalytic reactions followed pseudo-first-order kinetics and are discussed in terms of the Langmuir–Hinshelwood model.

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