Chemical modification of TiO2 by H2PO4−/HPO42− anions using the sol-gel route with controlled precipitation and hydrolysis: enhancing thermal stability

Elghniji, Kais; Saad, Mohamed El Khames; Araissi, Manel; Elaloui, Elimame; Moussaoui, Younes

doi:10.2478/s13536-014-0237-6

Cited by 18 publications

(9 citation statements)

References 38 publications

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“…Indeed, a broad band at 1074 cm -1 attributed to H2PO4 2- [54,55] is observed for material calcined at 380°C, it shifts to 1109 cm -1 after calcination at 600°C and splits into two bands at 1034 cm -1 and 1205 cm -1 after calcination at 800°C. The band at 1034 cm -1 was attributed to Ti-O-P bond [53]. After thermal treatment at 900°C the FTIR spectrum displayed the bands at 960, 979, 1049, 1092, 1205 et 1281 cm -1 that are characteristics of the P2O7 4from TiP2O7 phase [53].…”

Section: Study Of the Heteroelement Environmentmentioning

confidence: 98%

“…Solid state NMR experiments were run to investigate the evolution of the environment of the heteroatoms with the increase of the heating temperature when it was possible such as for TiO2 containing PO4 3-, Si 4+ and Al 3+ materials. TiO2 containing PO4 3calcined at 380, 600, 800 and 900°C have been analyzed by that was attributed to an unknown titanium crystalline phase [53]. The relative proportion of the crystalline phase TiP2O7 in which 1 phosphorus is coordinated via 3 oxygen to 3 titanium is about 80%.…”

Section: Study Of the Heteroelement Environmentmentioning

confidence: 99%

“…The band at 1034 cm -1 was attributed to Ti-O-P bond [53]. After thermal treatment at 900°C the FTIR spectrum displayed the bands at 960, 979, 1049, 1092, 1205 et 1281 cm -1 that are characteristics of the P2O7 4from TiP2O7 phase [53]. At 900°C the mesostructure has totally collapsed, the N2 physisorption isotherm is flat and particle size has strongly increased (83 nm at 900°C against 16 nm at 800°C): it is assumed that amorphous titanium phosphate species (structures with 3 and 4 P-O-Ti bonds) that surrounded the TiO2 anatase have crystallized in TiP2O7 and thus the glue effect was no more effective.…”

Section: Study Of the Heteroelement Environmentmentioning

confidence: 99%

“…The spectra were fitted with DMFit software[51] with 5 resonances at about 1.3, -5.1, -11.3, -16.7 and -28.4 ppm. Studies of amorphous or crystalline titanium phosphates have shown a correlation between connectivity and chemical shift[52,53]. As the connectivity increases, an upfield shift is observed.…”

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confidence: 99%

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Thermal stability and phase transformation of semi-crystalline mesostructured TiO2 in the presence of heteroelements

Jonas

Lebeau²,

Michelin³

et al. 2021

Microporous and Mesoporous Materials

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The effect of the introduction of heteroelement (Si, P, Al, Ge, Ga and Zr) by direct synthesis on the thermal stability of mesostructured titania prepared by the soft templating pathway has been investigated. All materials have been surfactant-extracted with EtOH and calcined at different temperatures up to 900°C. Ti 4+ can be partially substituted by most of the investigated heteroelements but they mainly form an oxide amorphous phase surrounding the titania anatase particles. Results obtained by SAXS, X-Ray diffraction, Raman spectroscopy and manometry nitrogen adsorption-desorption show that the crystallization of the amorphous titania into nanosized anatase particles and the transition from anatase to rutile occur at higher temperature with the addition of the heteroelement. Even if the lattice distortion introduced by the partial Ti 4+ substitution can participate to this phenomenon, it is mainly due the «glass» effect induced by the presence of the heteroelement in the TiO2 amorphous phase, which limits the growth of the nanosized anatase crystallites. However, when the crystallites reach a limit size, the collapse of the mesostructure occurs. With increasing the calcination temperature, the anatase titania particles become bigger and bigger, the transition from anatase to rutile takes place and the heteroelement can crystallize or be integrated in a crystalline phase. Among the considered heteroelements and by comparison with the bare mesostructured TiO2, the most beneficial effect is obtained in the presence of Si 4+ and PO4 3for which the mesostructure collapse at higher temperature by about two hundred Celsius degrees. Al 3+ and Ge 4+ enhance the thermal stability by about a hundred Celsius degrees and Ga 3+ or Zr 4+ have no significant effect on the temperature at which the mesostructure collapses.

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Section: Study Of the Heteroelement Environmentmentioning

confidence: 98%

Section: Study Of the Heteroelement Environmentmentioning

confidence: 99%

Section: Study Of the Heteroelement Environmentmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Thermal stability and phase transformation of semi-crystalline mesostructured TiO2 in the presence of heteroelements

Jonas

Lebeau²,

Michelin³

et al. 2021

Microporous and Mesoporous Materials

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“…Phosphates have been used as ceramic materials, catalysts, fluorescent materials, dielectric substances, metal‐surface treatments, detergents, food additives, in fuel cells, as pigments, and so on . Phosphate materials are recognized to have high biocompatibility and thermal stability, and are therefore expected to be useful as white pigments in cosmetics. White pigments that are not photocatalytically active are required for skin protection during cosmetic use.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and powder properties of titanium—Zinc phosphate white pigments

Onoda

Minamizawa

2017

Int J Applied Ceramic Tech

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Photocatalytically active titanium dioxide and zinc oxide are used as a white pigment for cosmetics, leading to decomposition of a certain degree of sebum on the skin upon exposure to the ultraviolet radiation in sunlight. Herein, as novel white pigments for use in cosmetics, titanium‐zinc phosphates were prepared from titanium sulfate, zinc sulfates, and phosphoric acid. The chemical composition, powder properties, photocatalytic activity, color phase, smoothness, and acid resistance of the titanium‐zinc phosphates were evaluated. Samples prepared at high titanium ratio were easy to be amorphous phase, on the other hand, samples prepared at high zinc ratio indicated the X‐ray diffraction peaks of zinc phosphate dihydrate. The photocatalytic activity of these titanium‐zinc phosphate particles was low; thus these pigments should not induce decomposition of sebum on the skin. All samples prepared in this study exhibited high reflectance within the range of visible light. The substitution with titanium is effective to improve acid resistance of zinc phosphate white pigments.

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Sol–gel reaction of titanium phosphonate alkoxide cluster

Tsukagoshi

Sato

Yamamoto

et al. 2022

Applied Organom Chemis

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The synthesis and properties of titanium phosphonate cluster molecules have been investigated; however, nothing has been done to study not only the catalytic ability of a hydrolyzed cluster but also a behavior of hydrolysis–polycondensation by solvents. The sol–gel reaction of [Ti4(μ3‐O)(OiPr)5(μ‐OiPr)3(O3PPh)3]·thf (Ti4P3Ph) was performed in tetrahydrofuran (THF), toluene, and acetone. The hydrolysis–polycondensation of Ti4P3Ph proceeded in THF and toluene, while Ti4P3Ph in acetone proceeded in two paths (hydrolysis–polycondensation and nonhydrolysis–polycondensation). The hydrolyzed Ti4P3Ph retained its cluster structure, while the calcined Ti4P3Ph at 300°C contained a collapsed cluster structure. The specific surface areas of the hydrolyzed Ti4P3Ph in THF, toluene, and acetone were 154, 302, and 7 m2 g−1, respectively. The photodegradation ability of the hydrolyzed Ti4P3Ph for methylene blue was confirmed by ultraviolet irradiation at 365 nm; however, that of the calcined Ti4P3Ph was not. It was considered that the calcined Ti4P3Ph did not retain its cluster structure. The photocatalytic ability of the hydrolyzed Ti4P3Ph was high in the order of toluene > THF > pristine > acetone. The gels retained cluster structure have higher photocatalytic ability than pristine cluster; however, the gel contained a collapsed cluster structure was found no catalytic ability.

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Chemical modification of TiO2 by H2PO4−/HPO42− anions using the sol-gel route with controlled precipitation and hydrolysis: enhancing thermal stability

Cited by 18 publications

References 38 publications

Thermal stability and phase transformation of semi-crystalline mesostructured TiO2 in the presence of heteroelements

Thermal stability and phase transformation of semi-crystalline mesostructured TiO2 in the presence of heteroelements

Synthesis and powder properties of titanium—Zinc phosphate white pigments

Sol–gel reaction of titanium phosphonate alkoxide cluster

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