Thermoanalytical characteristic of nanocrystalline brookite-based titanium dioxide

Ye, Xisheng; Sha, Jian; Jiao, Zhengkuan; Zhang, Lide

doi:10.1016/s0965-9773(98)00013-0

Cited by 81 publications

(49 citation statements)

References 13 publications

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“…Earlier reports on the application of sol-gel chemistry involving an organogelator and titanium isopropoxide (Ti(OiPr) 4 ) to generate TiO 2 nanostructures [60][61][62][63][64][65][66] were directed towards accomplishments of various morphologies, however expensive and complicated procedures were involved with the drawback of metal precursors precipitation and uncontrolled product structure. Similarly, earlier reports [67][68][69][70] suggested that the crystal structure of TiO 2 nanoparticles largely depended on the preparation method. Though considerable efforts have been made in the preparation of the nanosized TiO 2 , there is a lack of information on the preparation of TiO 2 nanoparticles or polymorphic TiO 2 (anastase or rutile phase) nanorods.…”

Section: Introductionsupporting

confidence: 53%

Effect of organic gelator template and preparation method on the structure and morphology of nanosized polymorphic titanium oxide using the sol–gel process

et al. 2011

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The TiO 2 nanoparticles of 25-30 nm or polymorphic TiO 2 nanorods (anatase or rutile) with a diameter of 65-75 nm and a length of several micrometers were synthesized by the modified sol-gel template process. The obtained nanoparticles were uniform as suggested by the scanning and transmission electron microscopic (SEM and TEM) images; similarly, TiO 2 nanorods obtained were of single anatase or of rutile phase after calcination at lower and higher temperatures, respectively, as characterized by X-ray diffraction.

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Section: Introductionsupporting

confidence: 53%

Effect of organic gelator template and preparation method on the structure and morphology of nanosized polymorphic titanium oxide using the sol–gel process

et al. 2011

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“…Therefore, post-synthetic temperature treatments, usually employed to improve the degree of crystallization, to reduce the sample or to remove organic precursors, should be carefully controlled in order to avoid the phase transformation of metastable polymorphs. The process of phase transformation has been widely investigated, especially on anatase, but its mechanism is not yet consolidated, to the point that all these transitions were observed: anatase to brookite to rutile [37], brookite to anatase to rutile [38], anatase to rutile [39,40], and brookite to rutile [41]. This is due to the fact that the phase transformation process depends on many factors, such as starting material, temperature, particle size, surface area [37], surface defect sites and presence of adsorbates [42].…”

Section: Synthesismentioning

confidence: 99%

Brookite: Nothing New under the Sun?

2017

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Advances in the synthesis of pure brookite and brookite-based TiO 2 materials have opened the way to fundamental and applicative studies of the once least known TiO 2 polymorph. Brookite is now recognized as an active phase, in some cases showing enhanced performance with respect to anatase, rutile or their mixture. The peculiar structure of brookite determines its distinct electronic properties, such as band gap, charge-carrier lifetime and mobility, trapping sites, surface energetics, surface atom arrangements and adsorption sites. Understanding the relationship between these properties and the photocatalytic performances of brookite compared to other TiO 2 polymorphs is still a formidable challenge, because of the interplay of many factors contributing to the observed efficiency of a given photocatalyst. Here, the most recent advances in brookite TiO 2 material synthesis and applications are summarized, focusing on structure/activity relation studies of phase and morphology-controlled materials. Many questions remain unanswered regarding brookite, but one answer is clear: Is it still worth studying such a hard-to-synthesize, elusive TiO 2 polymorph? Yes.

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“…Ye et al (8) studied the thermal behavior of nanocrystalline brookite by using thermogravimetry, differential thermal analysis, and diffraction. They observed a slow brookite to anatase phase transition below 1,053 K along with grain growth.…”

Section: General Implications Of Surface Enthalpies and Enthalpies Ofmentioning

confidence: 99%

Energetics of nanocrystalline TiO ₂

Ranade

Navrotsky

Zhang

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

516

458

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The energetics of the TiO2 polymorphs (rutile, anatase, and brookite) were studied by high temperature oxide melt drop solution calorimetry. Relative to bulk rutile, bulk brookite is 0.71 ؎ 0.38 kJ͞mol (6) and bulk anatase is 2.61 ؎ 0.41 kJ͞mol higher in enthalpy. The surface enthalpies of rutile, brookite, and anatase are 2.2 ؎ 0.2 J͞m 2 , 1.0 ؎ 0.2 J͞m 2 , and 0.4 ؎ 0.1 J͞m 2 , respectively. The closely balanced energetics directly confirm the crossover in stability of nanophase polymorphs inferred by Zhang and Banfield (7). An amorphous sample with surface area of 34,600 m 2 ͞mol is 24.25 ؎ 0.88 kJ͞mol higher in enthalpy than bulk rutile.

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Thermoanalytical characteristic of nanocrystalline brookite-based titanium dioxide

Cited by 81 publications

References 13 publications

Effect of organic gelator template and preparation method on the structure and morphology of nanosized polymorphic titanium oxide using the sol–gel process

Effect of organic gelator template and preparation method on the structure and morphology of nanosized polymorphic titanium oxide using the sol–gel process

Brookite: Nothing New under the Sun?

Energetics of nanocrystalline TiO ₂

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Thermoanalytical characteristic of nanocrystalline brookite-based titanium dioxide

Cited by 81 publications

References 13 publications

Effect of organic gelator template and preparation method on the structure and morphology of nanosized polymorphic titanium oxide using the sol–gel process

Effect of organic gelator template and preparation method on the structure and morphology of nanosized polymorphic titanium oxide using the sol–gel process

Brookite: Nothing New under the Sun?

Energetics of nanocrystalline TiO 2

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Energetics of nanocrystalline TiO ₂