Effects of the Brookite Phase on the Properties of Different Nanostructured TiO
            2
            Phases Photocatalytically Active Towards the Degradation of N‐Phenylurea

Carbon-titanium oxide nanocomposite (denoted as @C-TiO2) was successfully synthesized via hydrothermal method at 150°C for 24 h. The C-TiO2 nanocomposite was furtherly modified by adding an Ag metal dopant (denoted as Ag@C-TiO2) to improve and applied to the photocatalytic degradation of Sasirangan textile wastewater. The composite photocatalysts were characterized by XRD and UV–Vis DRS spectroscopies. XRD patterns showed that TiO2 in @C-TiO2 mainly consisted of a brookite phase, as indicated by a series sharp diffraction peak at 2θ = 27.2° (111), 31.5° (121) and 55.9° (241). The calculated band gap energy (Eg) derived from UV-Vis DRS spectra for TiO2, @C-TiO2, and Ag@C-TiO2 were 2.95 eV, 2.54 eV, and 2.74 eV, respectively. Ag@C-TiO2 photocatalyst was found to be active for the photocatalytic degradation of Sasirangan textile wastewater, as indicated by the change of wastewater color from dark to clear. The quantitative photocatalytic activity of Ag@C-TiO2 was evaluated in the degradation of methylene blue, whereas the conversion of methylene blue was 41.3%. The addition of Ag to @C-TiO2 is believed to play an essential role in the enhancement of photocatalytic activity.

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Direct synthesis of defective ultrathin brookite-phase TiO2 nanosheets showing flexible electronic band states

Chemical Communications ◽

10.1039/d0cc07214a ◽

2021 ◽

Author(s):

Weixin Zhao ◽

Shenqian Ma ◽

Jun Zhou ◽

Guolei Xiang

Keyword(s):

Direct Synthesis ◽

One Pot ◽

Electronic Band ◽

Flexible Electronic ◽

Tio2 Nanosheets ◽

Brookite Phase ◽

Thin Nanosheets

A one-pot protocol to directly prepare atomically-thin nanosheets of brookite-phase TiO2 is developed by hydrolyzing TiCl3 in formamide.

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Synthesis of Pure Brookite Nanorods in a Nonaqueous Growth Environment

Crystals ◽

10.3390/cryst9110562 ◽

2019 ◽

Vol 9 (11) ◽

pp. 562 ◽

Cited By ~ 5

Author(s):

Mahmoud Hezam ◽

Saif M. H. Qaid ◽

Idriss M. Bedja ◽

Fahhad Alharbi ◽

Mohammad Khaja Nazeeruddin ◽

...

Keyword(s):

Water Soluble ◽

Tetrabutyl Titanate ◽

X Ray Diffraction ◽

One Pot ◽

Growth Environment ◽

Transmission Electron ◽

Anatase Nanoparticles ◽

Na Ions ◽

Ti Complexes ◽

Brookite Phase

Brookite TiO2 is the most difficult TiO2 polymorph to synthesize. The available methods in the literature to produce brookite nanostructures mostly use water-based techniques for the preparation of water-soluble Ti complexes first, followed by a hydrothermal growth of the brookite nanostructures. Besides its multi-step nature, achieving a single brookite phase and optimizing the aqueous growth environment are all issues to be hardly controlled. In this work, pure brookite TiO2 nanorods are synthesized using tetrabutyl titanate Ti(OBu)4 and Sodium Fluoride (NaF) as precursor materials in a simple non-aqueous one-pot solvothermal process. Alcoholysis of only Ti(OBu)4 in ethanol resulted in pure anatase nanoparticles, while the addition of NaF was essential to promote the growth of highly pure brookite nanorods. The phase purity is confirmed by X-Ray Diffraction, Raman Spectroscopy, and High-Resolution Transmission Electron Microscopy. The growth mechanism is explained according to the Ostwald’s step rule, where Na+ ions are anticipated to have a potential role in driving the growth process towards the brookite phase.

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Acetaldehyde Photocatalytic Decomposition over Nanostructured TiO2 Sol-Gel Catalysts

MRS Proceedings ◽

10.1557/proc-1279-41 ◽

2010 ◽

Vol 1279 ◽

Author(s):

S. Castillo ◽

R. Camposeco ◽

R. Carrera ◽

M. Mujica ◽

P.Del Ángel ◽

...

Keyword(s):

Anatase Phase ◽

Sol Gel ◽

Photocatalytic Decomposition ◽

Test Results ◽

Rietveld Refinements ◽

Confined Spaces ◽

Tio2 Sol ◽

Uv Lamp ◽

Organic Gases ◽

Brookite Phase

AbstractTiO2nanoparticles were synthesized by the Sol-Gel method by using 2-propanol as solvent in acid medium (pH1). The samples were annealed at 200 and 500°C and were characterized by BET, XRD-Rietveld refinements, TEM and FTIR. The activity was evaluated by the acetaldehyde photodecomposition in an isolated chamber with an initial concentration of contaminant of 300 ppmv with oxygen (2%) assisted with a 365-nm UV lamp. The test results were compared with those obtained with a commercial catalyst (P25). Improved photoactivity (≍100 % of acetaldehyde in 150 min) was obtained with catalysts annealed at 200°C (TiO2-P-200°C), that showed nanoparticles (≍7 nm) and abundant anatase phase (≍ 63 %) coexist with the brookite phase (≍ 37 %), as well as irregular equiaxial morphology. The samples annealed at 500°C (TiO2-P-500°C), showed an increment in nanoparticles (≍22 nm), different ratio and phase composition (anatase-brookite-rutile), and therefore less activity (≍80 %). This high activity could be explained by the special ratio of anatase-brookite and the dimension of nanometric crystal size. The aforementioned characteristics could be useful in the degradation of reactive organic gases like acetaldehyde either in confined spaces or in the open air.

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Study of N-TiO2 Photocatalysts and their Catalytic Activities under Simulated Sunlight

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.918.27 ◽

2014 ◽

Vol 918 ◽

pp. 27-31 ◽

Cited By ~ 1

Author(s):

Sheng Jun Wang ◽

Lin Lin Wang ◽

Wen Yu Zhang

Keyword(s):

Band Gap ◽

Sol Gel ◽

Chemical Properties ◽

Physical Structure ◽

Band Gap Energy ◽

Simulated Sunlight ◽

Photocatalytic Activities ◽

N Doping ◽

Temperature Programmed ◽

Brookite Phase

N doped TiO2 was prepared by methods of sol-gel, precipitation, and temperature programmed nitridation (TPN) with NH3, respectively. The physical structure and chemical properties of the prepared N-TiO2 were characterized by DRS, XRD, XPS, and EPR spectra techniques. The result of XRD illustrated that all the samples were anatase, and no rutile or brookite phase. XPS and EPR indicated that N-TiO2 prepared by precipitate exist Ti3+ on the surface of TiO2. DRS pattern demonstrated N doping lead to the band gap narrow of all the samples, and the smallest band-gap energy of the samples prepared by precipitation was about 2.45eV. The photocatalytic activities were investigated by the photocatalytic degradation of methylene blue (MB) under simulated sunlight, and the highest activities reached to 75% during 120min.

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