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1.
Several TiO2-based photocatalytic systems that have considerable visible light response have been developed, such as the photodegradation
of organic pollutants on sensitized TiO2 by visible light, construction of visible-light-active novel TiO2 photocatalysts by matrix or surface modification. In this paper, we review briefly our recent progress in the TiO2 photocatalytic degradation of organic pollutants by visible light, some related work by other groups is also involved. 相似文献
2.
Katarzyna A. Michalow Andre Heel Andri Vital Martin Amberg Giuseppino Fortunato Kazimierz Kowalski Thomas J. Graule Mieczyslaw Rekas 《Topics in Catalysis》2009,52(8):1051-1059
Effect of W doping as well as a thermal treatment on the structural and photocatalytic properties of TiO2 produced by flame spray synthesis (FSS) were the subject of investigation. Structural properties were studied by means of
X-ray diffraction (XRD), BET adsorption isotherm and transmission electron microscopy (TEM). The surface condition was investigated
by X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC) and differential thermal and thermogravimetric
analysis (DTA-TGA). The photocatalytic properties were studied by optical measurements and photodecomposition of methylene
blue under visible irradiation. It was found that the photoactivity in the visible region was enhanced significantly by the
W-doping as well as by additional thermal treatment of those nanopowders. The obtained TiO2-W nanopowders exhibited higher performance under visible light than P25. 相似文献
3.
4.
The effects of superficial gas velocity (Ug), wavelength and intensity of ultraviolet (UV) light, oxygen and H2O concentration on the photocatalytic degradation of TCE (Trichloroethylene) over TiO2/SiO2 catalyst have been determined in an annulus fluidized bed photoreactor. The key factor in determining the performance of
the annulus fluidized bed photoreactor is found to be an optimum superficial gas velocity (Ug) that provides the optimum UV
lighttransmit through the proper size of bubbles in the photoreactor. The degradation efficiency of TCE increases with light
intensity but decreases with wavelength of the UV light and H2O concentration in the fluidized bed of TiO2/silica-gel photocatalyst. The optimum concentration of O2 for TCE degradation is found to be approximately 10%. The annulus fluidized bed photoreactor is an effective tool for high
TCE degradation with efficient utilization of photon energy.
This paper is dedicated to Professor Dong Sup Doh on the occasion of his retirement from Korea University. 相似文献
5.
C.-H. Lin C.-H. Lee J.-H. Chao C.-Y. Kuo Y.-C. Cheng W.-N. Huang H.-W. Chang Y.-M. Huang M.-K. Shih 《Catalysis Letters》2004,98(1):61-66
TiO2 nanotubes promoted with Pt metal were prepared and tested to be the photocatalytic dehydrogenation catalyst in neat ethanol for producing H2 gas (C2H5OHC3CHO +H2). It was found that the ability to produce H2, the liquid phase product distribution and the catlyst stability of these promoted nano catalysts all depended on the Pt loading and catalyst preparation procedure. These Pt/TiO2 catalysts with TiO2 nanotubes washed with diluted H2SO4 solution produced 1, 2-diethoxy ethane (acetal) as the major liquid phase product, while over those washed with diluted HCl solution or H2O, acetaldehyde was the major liquid phase product. 相似文献
6.
Jingfei Luan Mengjing Chen Wenhua Hu 《International journal of molecular sciences》2014,15(6):9459-9480
In this paper, ZnBiSbO4 was synthesized by a solid-state reaction method for the first time. The structural and photocatalytic properties of ZnBiSbO4 had been characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscope and UV-visible spectrometer. ZnBiSbO4 crystallized with a pyrochlore-type structure and a tetragonal crystal system. The band gap of ZnBiSbO4 was estimated to be 2.49 eV. The photocatalytic degradation of indigo carmine was realized under visible light irradiation with ZnBiSbO4 as a catalyst compared with nitrogen-doped TiO2 (N-TiO2) and CdBiYO4. The results showed that ZnBiSbO4 owned higher photocatalytic activity compared with N-TiO2 or CdBiYO4 for the photocatalytic degradation of indigo carmine under visible light irradiation. The reduction of the total organic carbon, the formation of inorganic products, SO42− and NO3−, and the evolution of CO2 revealed the continuous mineralization of indigo carmine during the photocatalytic process. One possible photocatalytic degradation pathway of indigo carmine was obtained. The phytotoxicity of the photocatalytic-treated indigo carmine (IC) wastewater was detected by examining its effect on seed germination and growth. 相似文献
7.
PSA [poly-(styrene-methyl acrylic acid)] latex particle has been taken into account as template material in SiO2 hollow spheres preparation. TiO2-doped SiO2 hollow spheres were obtained by using the appropriate amount of Ti(SO4)2 solution on SiO2 hollow spheres. The photodecomposition of the MB (methylene blue) was evaluated on these TiO2-doped SiO2 hollow spheres under UV light irradiation. The catalyst samples were characterized by XRD, UV-DRS, SEM and BET. A TiO2-doped SiO2 hollow sphere has shown higher surface area in comparison with pure TiO2 hollow spheres. The 40 wt% TiO2-doped SiO2 hollow sphere has been found as the most active catalyst compared with the others in the process of photodecomposition of
MB (methylene blue). The BET surface area of this sample was found to be 377.6 m2g−1. The photodegradation rate of MB using the TiO2-doped SiO2 catalyst was much higher than that of pure TiO2 hollow spheres. 相似文献
8.
TiO2 thin and thick films promoted with platinum and organic sensitizers including novel perylene diimide dyes (PDI) were prepared
and tested for carbon dioxide reduction with water under visible light. TiO2 films were prepared by a dip coating sol–gel technique. Pt was incorporated on TiO2 surface by wet impregnation [Pt(on).TiO2], or in the TiO2 film [Pt(in).TiO2] by adding the precursor in the sol. When tris (2,2′-bipyridyl) ruthenium(II) chloride hexahydrate was used as sensitizer,
in addition to visible light activity towards methane production, H2 evolution was also observed. Perylene diimide derivatives used in this study have shown light harvesting capability similar
to the tris (2,2′-bipyridyl) ruthenium(II) chloride hexahydrate. 相似文献
9.
采用离子交换法在粉煤灰微珠(FMS)表面沉积Ag@AgCl纳米颗粒,制备Ag@AgCl-FMS复合基底,采用水解-沉淀工艺,以TiCl4为钛源在复合基底表面再包覆纳米TiO2薄膜,经500℃煅烧2 h后得到Ag@AgCl- FMS-TiO2复合光催化剂. 对材料微观形貌、晶体结构、可见光光催化性能进行了表征与测试. 结果表明,复合基底表面包覆的TiO2薄膜均匀完整. 500℃煅烧后的物相为90%锐钛矿型TiO2和10%金红石型TiO2. 复合催化剂料在Ag@AgCl等离子共振效应的作用下,表现出明显的可见光响应,经可见光照射80 min后对甲基橙的降解率达99%,5次重复使用对甲基橙的降解率保持在85%. 相似文献
10.
For high solar conversion efficiency of dye-sensitized solar cells [DSSCs], TiO2 nanofiber [TN] and Ag-doped TiO2 nanofiber [ATN] have been extended to be included in TiO2 films to increase the amount of dye loading for a higher short-circuit current. The ATN was used on affected DSSCs to increase
the open circuit voltage. This process had enhanced the exit in dye molecules which were rapidly split into electrons, and
the DSSCs with ATN stop the recombination of the electronic process. The conversion efficiency of TiO2 photoelectrode-based DSSCs was 4.74%; it was increased to 6.13% after adding 5 wt.% ATN into TiO2 films. The electron lifetime of DSSCs with ATN increased from 0.29 to 0.34 s and that electron recombination was reduced. 相似文献
11.
Syed S. Amin Shu-you Li Xiaoxia Wu Weiqiang Ding Terry T. Xu 《Nanoscale research letters》2010,5(2):338-343
High-yield synthesis of TiO2 one-dimensional (1D) nanostructures was realized by a simple annealing of Ni-coated Ti grids in an argon atmosphere at 950 °C and 760 torr. The as-synthesized 1D nanostructures were single crystalline rutile TiO2 with the preferred growth direction close to [210]. The growth of these nanostructures was enhanced by using catalytic materials, higher reaction temperature, and longer reaction time. Nanoscale tensile testing performed on individual 1D nanostructures showed that the nanostructures appeared to fracture in a brittle manner. The measured Young’s modulus and fracture strength are ~56.3 and 1.4 GPa, respectively. 相似文献
12.
As a new type of photoelectrode, TiO2/Ni thin-film electrode was prepared by dip-coating technique. The structural and surface morphology of electrode was examined
by X-ray diffraction (XRD) and scanning electron microscope (SEM). Effects of initial phenol concentration, pH value, number
of film layers, voltage of electrical bias applied, variation of inorganic salt type and types of dissolved gas on the photoelectrocatalytic
(PEC) degradation of phenol using ultraviolet (UV) illuminated TiO2/Ni thin-film electrode were investigated. The mechanism of PEC degradation of phenol was also studied by analyzing reaction
intermediates. 相似文献
13.
CO impedes the low temperature (<170 °C) oxidation of C3H6 on supported Pt. Supported Au catalysts are very effective in the removal of CO by oxidation, although it has little propene oxidation activity under these conditions. Addition of Au/TiO2 to Pt/Al2O3 either as a physical mixture or as a pre-catalyst removes the CO and lowers the light-off temperature (T
50) for C3H6 oxidation compared with Pt catalyst alone by ~54 °C in a feed of 1% CO, 400 ppm C3H6, 14% O2, 2% H2O. 相似文献
14.
Effects of a photocatalyst, C60-modified Bi2TiO4F2, on pine kraft lignin under visible light irradiation were investigated, along with those of Bi2TiO4F2 and C60/TiO2 as references. The influences of pH, C60 mass fraction, and the initial lignin concentration on lignin conversion and yields of mono-phenolic products were investigated. Seven products were determined by GC/MS, including phenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, vanillin, acetovanillone, and homovanillic acid. The yields of products and lignin conversion were higher by C60/Bi2TiO4F2 than Bi2TiO4F2 and C60/TiO2. C60/Bi2TiO4F2 and C60/TiO2 were more stable than Bi2TiO4F2 upon repetitive recycling of catalyst. The effectiveness of C60/Bi2TiO4F2 declines 25%, whereas that of Bi2TiO4F2 declines 56.4% after being recycled five times. FTIR and HRTEM indicated that the deactivation of photocatalysts might be caused by lignin adsorbed on the surface of photocatalysts and the change in the crystal structure. 相似文献
15.
Seung-Joon Yoo Se-Il Lee Dong-Heui Kwak Kwang-Gil Kim Kyung-Jun Hwang Jae-Wook Lee Un-Yeon Hwang Hyung-Sang Park Jong-Ok Kim 《Korean Journal of Chemical Engineering》2008,25(5):1232-1238
Nanosized TiO2 sol synthesized by sol-gel method was successfully coated on the porous red clay tile (PRC tile) with micrometer sized pores.
PRC tile was first coated with a low-firing glaze (glaze-coated PRC tile) and then TiO2 sol was coated on the glaze layer. A low-fired glaze was prepared at various blending ratios with frit and feldspar, and
a blending ratio glazed at 700 °C was selected as an optimum condition. Then TiO2 sol synthesized from TTIP was dip-coated on the glazed layer (TiO2/glaze-coated PRC tile), and it was calcined again at 500 °C. Here, these optimum calcination temperatures were selected to
derive a strong bonding by a partial sintering between TiO2 sol particles and glaze layer. Photocatalytic activity on the TiO2/glaze-coated PRC tile was evaluated by the extent of photocatalytic degradation of methylene blue and acetaldehyde. Methylene
blue with the high concentration of 150 mg/l on the surface of TiO2/glaze-coated PRC tile was almost photodegraded within 5 hours under the condition of average UV intensity of 0.275 mW/cm2, while no photodegradation reaction of methylene blue occurred on the glaze-coated PRC tile without TiO2. Another photocatalytic activity was also evaluated by measuring the extent of photocatalytic degradation of gaseous acetaldehyde.
The photodegradation efficiency in TiO2/glaze-coated PRC tile showed about 77% photocatalytic degradation of acetaldehyde from 45,480 mg/l to 10,536 mg/l after the UV irradiation of 14 hours, but only about 16% in the case of the glaze-coated PRC tile. 相似文献
16.
This study investigated the removal of ammonia in wastewater by an electrochemical method using titanium electrodes coated
with ruthenium and iridium (RuO2–IrO2–TiO2/Ti) with low chlorine evolution over-voltage. The effects of operating parameters, including chloride ion concentration,
current density and initial pH, were also investigated. The results were evaluated primarily by considering the efficiency
of the elimination of NH4+-N. The removal of ammonia by electrochemical oxidation mainly resulted from the indirect oxidation effect of chlorine/hypochlorite
produced during electrolysis. The direct anodic oxidation efficiency of ammonia was less than 5%, and the current efficiency
was less than 10%. The ammonia removal followed pseudo-first-order kinetics. The electrochemical process can be applied successfully
as a final polishing step, or as an alternative method to biological nitrification. The process seems to be most beneficial
for small coastal cities 相似文献
17.
18.
Sang-Chul Jung 《Korean Journal of Chemical Engineering》2008,25(2):364-367
The photocatalytic activity of CVD grown films shows significant, non-linear (sigmoid-like) dependency on the film thickness.
However, the photocatalytic activity of sol-gel grown film is almost independent of the film thickness. The specific surface
area of sol-gel grown films is very small, regardless of the film thickness. Conversely, the specific surface area of CVD
grown films indicates significant thickness dependency. The specific area and photocatalytic activity were found to show very
similar dependencies on the film thickness. 相似文献
19.
Anatase phase nanocrystalline TiO2 powders were prepared by hydrothermal method with the TTIP (titanium tetra isopropoxide) at 200 oC in a stirred autoclave
system. The effects of synthesis conditions on the physical properties of catalyst were investigated by using XRD, SEM, DLS,
DSC and BET. The TiO2 powders obtained from the optimum condition showed uniform spherical shape, crystalline structure, submicron size with a
sharp size distribution and few agglomerates. The optimum synthesis conditions were obtained within the covered experimental
ranges. The photocatalytic activity of TiO2 powders prepared by the hydrothermal method was tested for photooxidation of methyl orange. 相似文献
20.
In this work, porous TiO2 hollow spheres with an average diameter of 100 nm and shell thickness of 20 nm were synthesized by a facile hydrothermal
method with NH4HCO3 as the structure-directing agent, and the formation mechanism for this porous hollow structure was proved to be the Ostwald
ripening process by tracking the morphology of the products at different reaction stages. The product was characterized by
SEM, TEM, XRD and BET analyses, and the results show that the as-synthesized products are anatase phase with a high surface
area up to 132.5 m2/g. Gas-sensing investigation reveals that the product possesses sensitive response to methanal gas at 200°C due to its high
surface area. 相似文献