Strategies for introducing titania onto mesostructured silica nanoparticles targeting enhanced photocatalytic activity of visible-light-responsive Ti-MSN catalysts

摘要: Abstract Titanium-mesostructured silica nanoparticles (Ti-MSN) catalysts which are excellent photocatalytic materials for the environment were prepared by supporting mesostructured (MSNs) with titanium species synthesized three different approaches: microwave and in situ ex electrochemical methods, denoted as Ti-MSN-M, Ti-MSN-I, Ti-MSN-E, respectively. The physicochemical properties of investigated via XRD, 29Si NMR, N2 adsorption-desorption, FTIR, ESR, UV-DRS analyses. Characterization results revealed that introduction mesoporous titania (MTNs) method onto MSNs (Ti-MSN-M) did not significantly affect framework. However, network Ti-MSN-I Ti-MSN-E was rather disrupted, particularly former catalyst, due to desilication accompanied isomorphous substitution Ti MSN framework form Si O bonds. also found be exchanged terminal hydroxyl groups all addition increased number oxygen vacancies (Vo) metal defect sites. Photocatalytic testing on decolorization Congo red (CR) resulted following order: (94%) > Ti-MSN-M (90%) > Ti-MSN-E (34%). Vo sites responsible lowering band gap decreasing electron–hole recombination, while great numbers bonds well large surface area pore volume active offered a good contact light enhance activity catalysts. A kinetic study demonstrated photodegradation followed pseudo-first-order Langmuir-Hinshelwood model. Ti-MSN-M maintained their activities up five runs without serious catalyst deactivation, indicating potential degradation dye wastewater. Mineralization measurements CR TOC BOD5 analyses after 3 h time 85.7% 87.6% using 83.7% 80.3% Optimization response methodology showed dosage, pH, TiO2 loading significant factors CR. This these two green technologies; MW have used synthesis various advanced greener more sustainable processes.