Narrow Results

The present work deals with the synthesis of bi-continuous macro and mesoporous crack-free titania–silica monoliths, with well-defined structural dimensions and high surface area. The work also highlights their potential photocatalytic environmental applications. The highly ordered titania–silica monoliths are synthesized through direct surface template method using organic precursors of silica and titania in the presence of surface directing agents such as pluronic P123 and PEG, under acetic acid medium. The monoliths are synthesized with different Ti/Si ratios to obtain monolithic designs that exhibit better photocatalytic activity for dye degradation. The titania–silica monoliths are characterized using XRD, SEM, EDAX, FT-IR, TG–DTA and BET analysis. The photocatalytic activity of the synthesized monoliths is tested on the photodegradation of a textile dye (acid blue 113). It is observed that the monolith with 7:3 ratio of Ti/Si showed significant photocatalysis behavior in the presence of UV light. The influence of various physico-chemical properties such as, solution pH, photocatalyst dosage, light intensity, dye concentration, effect of oxidants, etc. are analyzed and optimized using a customized photoreactor set-up. Under optimized conditions, the monoliths exhibited superior degradation kinetics, with the dye dissipation complete within 10min of photolysis. The mesoporous catalysts are recoverable and reusable up to four cycles of repeated usage.

The rapid removal of organic textile dye (Acid Red-85) using mesoporous TiO₂–SiO₂ monoliths as photocatalyst material has been studied. The 7:3 mole% ratios of TiO₂ and SiO₂ within the framework provided a well-ordered cage-like monolithic design with high surface area and pore volume that facilitated faster and efficient degradation of the dye effluents. The photocatalyst has been characterized using XRD, TEM-SAED, UV–Vis-DRS, PL, TGA and BET analysis. The influence of various photocatalytic operational parameters, such as solution pH, dopant stoichiometry, catalyst dosage, dye concentration, kinetics, photo-oxidizers, etc., which could influence on the degradation efficiency, has been studied.