13780-39-7Relevant articles and documents
Photocatalytic characteristics of nanometer-sized titania powders fabricated by a homogeneous-precipitation process
Lee, Kang Ryeol,Kim, Sun Jae,Song, Jae Sung,Lee, Ju Hyeon,Chung, Yun Joong,Park, Sung
, p. 341 - 345 (2002)
The photocatalytic characteristics of nanometer-sized TiO2 powder prepared by a homogeneous-precipitation process (HPP) were compared with those of a commercial powder to determine which powder was better able to remove metal ions, such as lead and copper, from aqueous equimolarmetal-ethylenediaminetetraacetic acid (EDTA) solution. In aqueouslead-EDTA solution, the TiO2 powder fabricated by HPPhad 3.5 times higher initial adsorption of lead ion and a 1.5 times faster rate for the complete elimination of lead ions than did the commercial powder. In an aqueous copper-EDTA solution, the TiO2 powder fabricated by HPP also showed higherinitial adsorption and a faster elimination rate for copper ions than did the commercial powder. Similarly, the photocatalyticproperties were enhanced as the specific surface area increased, and the TiO2 powder fabricated by HPP, which consisted of coagulated primary particles 20 nm in size, with chestnut-burr shapes, had a larger specific surface area (～180 m2/g) than that of the commercial powder (～55 m2/g).
Phase formation, crystal structure, and electrical conductivity of triple phosphates of alkali metals and titanium
Asabina,Pet'Kov,Boguslavskii,Malakho,Lazoryak
, p. 1167 - 1175 (2006)
For triple phosphates of composition A0.5A'0.5 Ti2(PO4)3 (A-A'=Li-Na, Na-K, K-Rb), phase formation is studied, the crystal structure is refined, and the electrical conductivity is measured. The compounds are classified with the NaZr 2(PO4)3 structure type (NZP, space group R 3? c). The phosphate frameworks are built of TiO6 octahedra and PO4 tetrahedra. Extraframework positions M1 are fully occupied by randomly distributed alkali cations. Positions M2 are vacant. Correlations are found between the structural distortion and electrical conductivity of the phosphates, on one hand, and the alkali cation size, on the other. Pleiades Publishing, Inc. 2006.
Photocatalytic degradation of methylene blue under UV and visible light by brookite-rutile bi-crystalline phase of TiO2
Kim, Min Gu,Lee, Ji Eun,Kim, Kang Seok,Kang, Jeong Min,Lee, Jeong Hoon,Kim, Kwang Ho,Cho, Min,Lee, Seung Geol
, p. 3485 - 3497 (2021/03/03)
The phase junction of TiO2 nanoparticles plays an essential role in improving photocatalytic activity. Mixed phase brookite-rutile TiO2 nanoparticles with different phase compositions were synthesized through a hydrolysis method using nitric acid of different concentrations. The bi-crystalline phase was characterized by X-ray diffraction (XRD), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and Brunauer-Emmett-Teller (BET), UV-vis diffuse reflectance spectroscopy (DRS) and Photoluminescence (PL) analysis. Photoelectrochemical properties were investigated by transient photocurrent density (TPR) and electrochemical impedance spectroscopy (EIS). XRD and Raman results revealed that the brookite content increased in the sample when increasing the HNO3 concentration. The prepared mixed-phase TiO2 nanoparticles have mesopores with large surface areas ranging from 48.81 to 89.95 m2 g-1. UV-vis spectra showed a redshift of absorption edge from 398 nm to 408 nm with increasing brookite content. The optical band gaps which were obtained from the UV-vis spectra were decreased with increasing brookite content. Photoluminescence results showed that the sample prepared with 5.0 M nitric acid (BCTi-4) showed the lowest emission due to the electron-hole recombination. Furthermore, BCTi-4 revealed the highest photocurrent density of 6 μA cm-2 and the smallest Rct values of 3.30 kΩ. The photocatalytic properties of prepared samples were evaluated by the degradation of methylene blue under UV and visible light irradiation. The BCTi-4 exhibited the highest degradation rate that completely degraded methylene blue after 3 hours of UV irradiation and 36 hours under visible light irradiation. This was attributed to the synergetic effect of phase junction of brookite and rutile, which reduces the recombination of photoexcited electron-hole pairs and the optimal ratio of brookite and rutile. This journal is
Transesterification Catalyst and Method for Producing Biodiesel Fuel Using Transesterification Catalyst
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, (2015/12/30)
[Problem] To provide a catalyst for production of a biodiesel fuel, which is capable of producing a biodiesel fuel with high selectivity, at a high yield, and at a low cost even in the presence of a water content and a free fatty acid, and a biodiesel fuel production method using the catalyst. [Solution] Use of a titanium-containing mesoporous silica containing Ti and Si as skeleton constituent elements and having a pore diameter of 5 nm or greater as a transesterification catalyst enables a biodiesel fuel to be produced with high selectivity at a high yield through transesterification between an oil and an alcohol.
