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1.
Carbon nanotubes (CNTs)/Ta3 N5 nanocomposite is presented as a novel photocatalyst working under visible light irradiation. The results of Fourier transform infrared analyses and transmission electron microscopy indicate that a good interfacial combination has formed between CNTs and Ta3 N5 nanoparticles. The CNTs/Ta3 N5 nanocomposite shows strong absorption in the visible light range compared with pure Ta3 N5 and has a bandgap energy of 2.01 eV. The photocatalytic experiments show that the nanocomposite has a higher photocatalytic activity than Ta3 N5 nanoparticles. 相似文献
2.
We present a novel approach for the fabrication of α-Fe2 O3 -sensitized TiO2 nanosheets. The TiO2 nanosheets with partly curly surfaces and large surface areas can rapidly absorb the methylene blue (MB). The absorption and degradation of MB are investigated. Results show that the photocatalytic activities of α-Fe2 O3 make the MB degradation efficient under visible light irradiation. By coupling two semiconductor systems, electrons can be injected from an excited small band gap semiconductor into TiO2 under visible light. Such a modification is expected to lead to new or enhanced properties. 相似文献
3.
Huaming Yang Ke Zhang Rongrong Shi Aidong Tang 《Journal of the American Ceramic Society》2007,90(5):1370-1374
Uniform CeO2 / TiO2 composite nanoparticles with different Ce/Ti molar ratios have been successfully synthesized via the sol–gel method. The samples were characterized using differential thermal analysis (DTA), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The surface state analysis by means of X-ray photoelectron spectroscopy (XPS) shows that the Ti element mainly exists as a chemical state of Ti4+ , while the Ce element exists as a mixture of Ce3+ and Ce4+ oxidation states. The photocatalytic degradation of methyl orange (MeO) in CeO2 / TiO2 suspension was investigated. The results indicate that the CeO2 /TiO2 nanocomposites show higher photocatalytic activity than pure TiO2 . Photodegradation of MeO can be improved by increasing the Ce/Ti molar ratio in the initial 15 min. 相似文献
4.
TiO2 /SnO2 nanonecklace-structured hybrid nanofibers have been prepared via an electrospinning method. These hybrid nanofibers are characterized with SnO2 -rich beads and pure TiO2 chains. It is found that TiO2 in the beads shows a rutile structure, and the one in the chains is entirely composed of anatase phase. This novel microstructure enhanced the photocatalytic activity, as well as its ideal recyclable character. We believe that this fire-new type of nanofiber may potentially serve as a new generation photocatalyst in environmental remediation. 相似文献
5.
CdSe-modified rutile TiO2 nanocrystals with mercaptoacetic acid as a stabilizer were prepared by the hydrothermal method. The photoactivities of the new photocatalyst under visible light illumination were demonstrated by the degradation of methylene blue (MB). The effects of CdSe content on the absorption spectra and photoactivities were discussed. After sensitization, TiO2 significantly responded to visible light illumination and the visible light photoactivities also increased. 相似文献
6.
Jungho Ryu Byung-Dong Hahn Jong-Jin Choi Woon-Ha Yoon Byoung-Kuk Lee Joon Hwan Choi Dong-Soo Park 《Journal of the American Ceramic Society》2010,93(1):55-58
Porous photocatalytic TiO2 thin films were fabricated by the leaching technique, followed by aerosol deposition. Mixed powders of TiO2 and β-tricalcium phosphate (TCP) were aerosol deposited at room temperature for the initial fabrication of composite films. After the β-TCP phases were leached out from the composite films in a diluted HCl aqueous solution for 24 h, porous TiO2 films remained on the substrate. To fabricate these porous films, the β-TCP content was varied from 10 to 45 wt% and submicrometer-sized pores were formed after leaching. The porous TiO2 films showed strong initial photocatalytic activities due to the adsorption effect of the pores and the enlarged surface area. 相似文献
7.
Jinxiu Wang Xue Yang Jing Chen Jiangjun Xian Sugang Meng Yi Zheng Yu Shao Danzhen Li 《Journal of the American Ceramic Society》2014,97(1):267-274
In this study, pure Ag4V2O7 was synthesized via hydrothermal method without surfactant at different temperatures (100°C, 120°C, and 140°C) and pH values (4 and 5) for the first time. Moreover, Ag4V2O7 nanoparticles with homogeneous size distribution about 200–300 nm can be obtained by adding polyvinylpyrrolidone to the synthesis system. Effects of hydrothermal synthesis conditions on photophysical properties and photocatalytic activity of Ag4V2O7 were investigated systematically. Ag4V2O7 sample prepared at 120°C and pH = 4 had the optimal photocatalytic activity among these samples, which almost completely degraded 10 ppm Rhodamine B within 3 h under visible light irradiation (420 nm < λ < 800 nm). The degradation products were measured by liquid chromatography–mass spectroscopy. The active species involved in the degradation process were analyzed by means of adding active species scavengers, electron spin resonance techniques, and photoelectrochemical experiments. A possible mechanism for photocatalytic degradation of organic pollutants on Ag4V2O7 photocatalyst was proposed and discussed preliminarily. 相似文献
8.
Churl Hee Cho Do Kyung Kim Do Hyeong Kim 《Journal of the American Ceramic Society》2003,86(7):1138-1145
Monodispersed spherical TiO2 particles were prepared by hydrothermal crystallization and/or calcination of spherical amorphous particles, synthesized by thermal hydrolysis of TiCl4 . The crystallized spherical particles were secondary agglomerates of primary nanocrystallites. Different crystallization routes and conditions provided the spherical TiO2 particles with wide particle characteristics, such as the fraction of crystallization, the size and shape of the primary nanocrystallites, and the specific surface area. The photocatalytic activity showed complex dependence on the crystallization routes and conditions. The complex dependence behavior could be explained by combining the effects of the fraction of crystallization, the specific surface area, and the adsorption ability for hydroxyl ions. Especially, in the present study, the hydrothermally crystallized TiO2 particles with large primary nanocrystallites showed the highest photocatalytic activity. The high photocatalytic activity mainly resulted from the high surface adsorption ability for hydroxyl ions, which was closely related to the well-developed (flat and faceted) morphology of primary nanocrystallite. 相似文献
9.
Guangxiu Cao Yaogang Li Qinghong Zhang Hongzhi Wang 《Journal of the American Ceramic Society》2010,93(1):25-27
La-doped TiO2− x F x (La–TiO2− x F x ) powders were prepared by the sol–gel method. X-ray diffraction results showed that La efficiently inhibited grain growth. X-ray photoelectron spectroscopy spectra revealed that La2 O3 and O–Ti–F bonds have formed, the La2 O3 maintained the high surface area of TiO2− x F x after calcination at a temperature above 500°C, while the O–Ti–F bonds increased the oxidation potential of the photogenerated hole in the valence band. The UV-vis spectroscopy of the La–TiO2− x F x showed that the presence of intraband gap states was likely responsible for its absorption of visible light. When the molar ratios of La and F to Ti were 1.5:100 and 5:100, respectively, and calcined at 500°C, the photocatalytic degradation rate of methylene blue over La–TiO2− x F x was about 1.5 times higher than that of F-doping TiO2 . 相似文献
10.
采用混合溶剂法,通过改变钛酸四丁酯(TBOT)的量合成一系列不同比例的RF@TiO2核-壳结构,于氮气气氛600℃下煅烧得到meso-C@TiO2,进一步对所得产物表面进行贵金属沉积最终得到meso-C@TiO2@Ag复合光催化剂.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、全自动比表面积及微孔物理吸附仪(BET)等对样品的成份、形貌和结构进行了表征.结果表明,成功制备了meso-C@TiO2@Ag三元介孔复合光催化材料,并且比表面积达到173.9 m2/g.在可见光照射下,以降解亚甲基蓝为模型,探讨了TBOT用量以及Ag负载量对产物光催化性能的影响.研究发现,当加入TBOT的量为0.3mL、AgNO3的投入量为10wt%时,所制备的meso-C@TiO2@Ag对亚甲基蓝的降解效果最佳,40 min内降解率接近100%,性能明显优于市售的纳米二氧化钛P25. 相似文献
11.
以钛酸四丁酯为钛源,硝酸银和硼酸为掺杂剂,采用溶胶-凝胶法制备硼银共掺杂二氧化钛催化剂,采用紫外可见光漫反射光谱(UV-Vis DRS)、扫描电镜(SEM)、能谱仪(EDS)、X射线衍射光谱(XRD)对样品进行表征。以400W金卤灯为光源降解20mg/L甲基橙溶液,光照30min分别探究Ag摩尔分数、B摩尔分数、煅烧温度、煅烧时间等制备条件对光催化剂性能的影响。结果表明,银硼共掺杂二氧化钛是结构不规则、大小不均匀的块状颗粒,硼、银离子成功掺入TiO2中。硼银元素的掺入使TiO2的光谱响应范围向可见光方向发生了明显红移。当煅烧温度为400℃,煅烧时间为2h,Ag摩尔分数为1.2%,B摩尔分数为6mol%时,Ag-B-TiO2降解效果最为显著,降解率为89.47%。 相似文献
12.
Yingying Lv Yan Ding Jiahong Zhou Wenmin Xiao Yuying Feng 《Journal of the American Ceramic Society》2009,92(4):938-941
The doping of titanium dioxide (TiO2 ) with various metal or nonmetal elements has been considered as an effective strategy to extend the photoactive wavelength region to visible light. In this paper (nitrogen [N] and sulfur [S])-codoped anatase TiO2 nanoparticles were prepared via a sol–gel route, followed by a heat treatment at elevated temperatures. The as-prepared samples were extensively characterized by X-ray diffraction, UV–Vis absorption spectroscopy, and X-ray photoelectron spectroscopy. The N, S-codoped TiO2 nanoparticles showed a strong visible light absorption and exhibited an enhanced photocatalytic activity for the degradation of methylene blue as compared with the pure, N- or S-doped TiO2 under either UV light or solar light irradiation. 相似文献
13.
The solubility of TiO2 in tetragonal ZrO2 is 13.8±0.3 mol% ui 1300°C, 14.9±0.2 mol% at 1400°C, and 16.1±0.2 mol% at 1500°C. These solid solutions transform to metastable monoclinic solid solutions without compositional change on cooling to room temperature. 相似文献
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15.
Magdalena Janus Beata Tryba Ewelina Kusiak Tomoki Tsumura Masahiro Toyoda Michio Inagaki Antoni W. Morawski 《Catalysis Letters》2009,128(1-2):36-39
TiO2 nanoparticles (C-TNT) with high visible light activity were obtained by carbonization of titania nanotubes (TNT) in an ethanol atmosphere under elevated pressure at 180 and 220 °C. New material was characterised by means of UV–Vis/DR, FTIR/DRS, TEM, and XRD. The photocatalytic activity was tested during monoazo dye decomposition under artificial solar light irradiation. Modified photocatalyst (220 °C, 4 h) had higher photocatalytic activity than both the pristine and commercial P25 catalysts. 相似文献
16.
Haiqing Liu Jinxia Yang Jianhe Liang Yingxing Huang Chunyi Tang 《Journal of the American Ceramic Society》2008,91(4):1287-1291
In this paper, we fabricate ZnO nanofibers and nanoparticles through electrospinning precursor solution zinc acetate(ZnAc)/cellulose acetate(CA) in mixed-solvent N , N -dimethylformamide/acetone. Depending on the posttreatment of precursor ZnAc/CA composite nanofibers, both ZnO nanofibers and nanoparticles were synthesized after calcination of precursor nanofibers. The morphology and crystal structure of the ZnO nanofiber and nanoparticle were characterized by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and X-ray diffraction. It was found that the mean diameter of the ZnO nanofiber and nanoparticle was ca. 78 and 30 nm, respectively. The photo-degradation of dye molecules such as Rhodamine B and acid fuchsin catalyzed by the ZnO nanofiber and nanoparticle was evaluated under the irradiation of visible light. Both morphological ZnO species showed strong photocatalytic activity. However, the ZnO nanofiber in the form of nanofibrous mats showed much higher efficiency than the nanoparticle although the latter has a smaller size than the former. The porous structure of ZnO nanofibrous mats is believed to improve the contacting surface areas between the catalyst and the dye molecules, while the aggregation of ZnO nanoparticle in the solution lowers the photocatalytic efficiency. 相似文献
17.
Nicholas J. Welham 《Journal of the American Ceramic Society》2000,83(5):1290-1292
Titanium diboride can be produced by ball-milling a mixture of TiO2 , B2 O3 , and Mg metal for between 10 and 15 h. The reaction was found to be completed during the milling with no evidence of residual Mg. The unwanted phase, MgO, was readily removed by leaching in acid. The leached powder obtained after 15 h milling had a particle size of <200 nm and was highly faceted. The particle size decreased to ∼50 nm after 100 h milling and seemed to be relatively monodisperse. Scherrer calculation of the crystallite size showed that the product particles were probably single crystal. 相似文献
18.
The formation of TiO2 powders by oxygenolysis of TiCI4 was studied with emphasis on the effects of reaction conditions on the particle size of the products. The particle size of TiO2 (anatase) decreased with increasing reaction temperature or O2 concentration and with decreasing TiCI4 concentration. The results are compared with those for the oxygenolysis of AlBr3 and SiCI4 . It was found that the reactivity of metal halides with O2 is closely related to the ease of dissociation of the first halogen atom. 相似文献
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20.
Masayuki Fujimoto Tomoya Ohno Hisao Suzuki Hiroshi Koyama Junzo Tanaka 《Journal of the American Ceramic Society》2005,88(11):3264-3266
We characterized SiO2 –TiO2 nano-hybrid particles, prepared using the sol–gel method, using high-resolution transmission microscopy. A few nanometer-ordered TiO2 anatase crystallites could be observed on the monodispersed SiO2 nanoparticle surface. The quantum size effect of the TiO2 anatase crystallites is attributed to the blue shift of the absorption band. The rough surface of the SiO2 –TiO2 nano-hybrid particles was derived from the developed growth planes of the TiO2 anatase crystallites, grown from fully hydrolyzed Ti alkoxide that did not react with acetic acid during the crystallization process at 600°C thermal annealing. 相似文献