Effect of sulfation methods on TiO2–SiO2 sol–gel catalyst acidity

López, Tomás; Bosch, P.; Tzompantzi, Francisco; Gómez, R.; Navarrete, Juan T. López; López-Salinas, E.; Llanos, M. E.

doi:10.1016/s0926-860x(99)00541-4

Cited by 70 publications

(60 citation statements)

References 16 publications

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“…However, the peak intensity and position have changed in the spectrum of TD-750. The dominant peak at about 530.4 eV is still characteristic of TiO 2 , and the peak at about 533.4 eV is corresponding to SiO 2 which is the main component of diatomite [35]. Additionally, the XPS shift of O 1s is another evidence of the presence of Ti-O-Si bond.…”

Section: Morphology Investigationmentioning

confidence: 98%

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Synthesis, characterization and activity of an immobilized photocatalyst: Natural porous diatomite supported titania nanoparticles

Wang

Godoi

Sun

et al. 2015

Journal of Colloid and Interface Science

120

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Diatomite, a porous non-metal mineral, was used as support to prepare TiO 2 /diatomite composites by a modified sol-gel method. The as-prepared composites were calcined at temperatures ranging from 450 to 950 o C. The characterization tests included X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with an energy-dispersive X-ray spectrometer (EDS), High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption/desorption measurements. The XRD analysis indicated that the binary mixtures of anatase and rutile exist in the composites. The morphology analysis confirmed the TiO 2 particles were uniformly immobilized on the surface of diatom with a strong interfacial anchoring strength, which leads to few drain of photocatalytic components during practical applications. In further XPS studies of hybrid catalyst, we found the evidence of the presence of Ti-O-Si bond and increased percentage of surface hydroxyl. In addition, the adsorption capacity and photocatalytic activity of synthesized TiO 2 /diatomite composites were evaluated by studying the degradation kinetics of aqueous Rhodamine B under UV-light irradiation.The photocatalytic degradation was found to follow pseudo-first order kinetics according to the Langmuir-Hinshelwood model. The preferable removal efficiency was observed in composites by 750 o C calcination, which is attributed to a relatively 2 appropriate anatase/rutile mixing ratio of 90/10.

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Section: Morphology Investigationmentioning

confidence: 98%

“…458.2 eV (for pure TiO 2 ) to 459.4 eV (in presence of diatomite) might be related to higher electronegativity of Si in comparison to Ti [34]. It is suggested that the TiO 2 NPs are combined on the surface of diatom via Ti-O-Si bond [35,36].…”

Section: Morphology Investigationmentioning

confidence: 99%

Synthesis, characterization and activity of an immobilized photocatalyst: Natural porous diatomite supported titania nanoparticles

Wang

Godoi

Sun

et al. 2015

Journal of Colloid and Interface Science

120

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“…In general, pure titania only has Lewis acid properties whereas the silanol groups (Si-OH) of silica are so weakly acidic that the material is generally classified as inert. However, SiO 2 -TiO 2 mixed oxides exhibit a large number of acidic sites and acid strength which depend on the metal oxide relative content, nature and method of preparation [20,21]. The new acidic sites are assumed to be produced by charge imbalance localized at the Si-O-Ti bonds owing to the difference in coordination geometries of Si and Ti [22].…”

Section: Introductionmentioning

confidence: 99%

Silica–Titania mixed Oxides: Si–O–Ti Connectivity, Coordination of Titanium, and Surface Acidic Properties

et al. 2008

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A series of SiO 2 -TiO 2 mixed oxides was prepared by the sol-gel route, and the influence of several important preparation parameters (Ti precursors, content, and calcination temperature) on the Si-O-Ti connectivity, coordination of titanium and surface acidity has been studied using various analytical techniques. The solids obtained were largely amorphous and characterized by Ti enrichment on surfaces with low titanium content; however, the addition of titanium greater than 50 mol% into the SiO 2 matrix led to significant phase separation of crystalline anatase. The Ti atoms are tetrahedrally coordinated with Si/Ti ratios higher than 10 and gradually enter into octahedral positions in the silica matrix with further increase in the titanium content. High-temperature treatment can break Si-O-Ti linkages and eliminate hydroxyl groups, resulting in a decrease in acid site density.

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“…A potentially cost-effective way to improve the photocatalysts performance is increasing the number and the adsorption capacity of surface acid sites since PCO activity has been shown to increase with catalyst surface acidity [11,12]. Sulphated metal oxides are particularly effective acid catalysts [13][14][15], indicating a promising way of development.…”

Section: Introductionmentioning

confidence: 99%

Gas-phase Photocatalytic Oxidation of Acrylonitrile on Sulphated TiO2: Continuous Flow and Transient Study

2010

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Effect of sulfation methods on TiO2–SiO2 sol–gel catalyst acidity

Cited by 70 publications

References 16 publications

Synthesis, characterization and activity of an immobilized photocatalyst: Natural porous diatomite supported titania nanoparticles

Synthesis, characterization and activity of an immobilized photocatalyst: Natural porous diatomite supported titania nanoparticles

Silica–Titania mixed Oxides: Si–O–Ti Connectivity, Coordination of Titanium, and Surface Acidic Properties

Gas-phase Photocatalytic Oxidation of Acrylonitrile on Sulphated TiO2: Continuous Flow and Transient Study

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