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Enhancement of formaldehyde degradation by amine functionalized silica/titania films

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Journal of Environmental Sciences 2009年第12期21卷 1741-1746页

作者： Somjate Photong Virote Boonamnuayvitaya Department of Chemical Engineering King Mongkut's University of Technology Thonburi

Doping amine functional groups into SiO2/TiO2 films for enhancing the decomposition of formaldehyde has been investigated using the modified sol-gel method to prepare organic-inorganic hybrid photocatalysts via the co-condensation reaction of methyltrimethoxysilane （MTMOS） and amine functional groups, n-（2-Aminoethyl）-3-aminopropyl-trimethoxysilane （AEAPTMS） and 3-aminopropyl-trimethoxysilane （APTMS） were selected to study the effect of amine functional groups on the enhancement of formaldehyde adsorption and degradation under a UV irradiation process. Physicocbemical properties of prepared photocatalysts were characterized with nitrogen adsorption-desorption isotherms measurement, X-ray diffraction （XRD） and Fourier transform infrared （FT-IR） spectroscopy. The results indicated that the APTMS/SiO2/TiO2 film demonstrated a degradation efficiency of 79% superior to those of SiO2/TrO2 and AEAPTMS/SiO2/TiO2 films due to the synergetic effect of adsorption and photocatalytic properties. The APTMS/SiO2/TiO2 film can be recycled with about 7% decreasing of degradation efficiency after seven cycles.

关键词： photocatalysis titania functional groups formaldehyde

titania-supported iridium catalysts for dehydrogenative synthesis of benzimidazoles

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Chinese Chemical Letters 2020年第3期31卷 605-608页

作者： Kenji Wada Han Yu Qi Feng Department of Chemistry for Medicine Kagawa UniversityMiki-ChoKita-GunKagawa 761-0793Japan Department of Advanced Materials Science Kagawa UniversityTakamatsuKagawa 761-0396Japan

In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridium catalysts showed excellent activities under mild reaction conditions.Remarkably,the low-temperature activity of iridium catalyst was significantly affected by titania supports,and the reaction of 1,2-phenylenediamine and benzyl alcohol in the presence of rutilesupported catalysts proceeded smoothly at 100℃to give 2-phenylbenzimidazole in high yields of up to 88%,On the other hand,catalysts supported on anatase generally showed poor activity at 100℃.A significant relationship between CO uptake and the activity of titania-supported catalysts has been reported,indicating that well-reduced iridium species on rutile would be responsible for the predominant catalytic activity.The present results suggest the importance of the selection of suitable titania supports for the iridium catalysts.

关键词： Benzimidazole Iridium titania Heterogeneous catalysts Dehydrogenation

Ultrafine polycrystalline titania nanofibers for superior sodium storage

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Journal of Energy Chemistry 2019年第11期28卷 153-161页

作者： Zhidan Diao Daming Zhao Chunxiao Lv Hongli Liu Dongjiang Yang Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Environmental Science and Engineering Collaborative Innovation Centerfor Marine Biomass FibersMaterials and Textiles of Shandong ProvinceQingdao UniversityQingdao 266071ShandongChina

Sodium ion batteries have a huge potential for large-scale energy storage for the low cost and abundance of sodium resources. In this work, a novel structure of ultrafine polycrystalline TiO2 nanofibers is prepared on nickel foam/carbon cloth by a simple vapor deposition method. The as-prepared TiO2 nanofibers show excellent performance when used as anodes for sodium-ion batteries. Specifically, the TiO2 nanofibers@nickel foam electrode delivers a high reversible capacity of 263.2 m Ahg^-1 at 0.2 C and maintains a considerable capacity of 144.2 m Ahg^-1 at 10 C. The TiO2 nanofibers@carbon cloth electrode also shows excellent high-rate capability, sustaining a capacity of 148 m Ahg^-1 after 20 0 0 cycles at 10 C. It is believed that the novel nanofibrous structure increases the contact area with the electrolyte and greatly shortens the sodium ion diffusion distance, and meanwhile, the polycrystalline nature of nanofibers exposes more intercalation sites for sodium storage. Furthermore, the density functional theory calculations exhibit strong ionic interactions between the exposed TiO2(101) facets and sodium ions, leading to a preferable sodiation/desodiation process. The unique structural features endow the TiO2 nanofibers electrodes great advantages in rapid sodium storage with an outstanding high-rate capability.

关键词： Polycrystalline titania Nanofibers Sodium storage High-rate capability

Sol-gel derived bioactive hydroxyapatite/titania composite films on Ti6Al4V

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Journal of University of Science and Technology Beijing 2006年第5期13卷 469-475页

作者： Bing Su Guoqing Zhang Xudong Yu Chengtao Wang School of Mechanical and Power Energy Engineering Shanghai Jiaotong University Shanghai 200030 China Military Engineering Department Artillery Academy Hefei 230031 China

The composite films consisting of the titania gel impregnated with hydroxyapatite （HAP） submicron particles were prepared on commercial Ti6A14V plates processed by a sol-gel route. HAP powders were synthesized based on wet chemical precipitation method with Ca（NO3）2.4H2O and （NH4）2HPO4 as starting reagents. After being calcined at 900℃, HAP powders were ultrasonically scattered in ethanol to produce HAP sol. The titania sol was prepared using titanium （IV） isopropoxide {Ti[OCH（CH3）2]4} as precursor. Both the titania sol and the HAP/titania mixture were sequentially spin-coated on the substrates and calcined at various temperatures. The characteristics and mechanical adhesion of the composite films were investigated. The results show that the as-prepared films are dense, homogeneous, well-crystallized, and there is a good interfacial adhesion between the film and the substrate. The in vitro bioactivities of these films were discussed based on the analysis of the variations of Ca and P concentrations in the simulated body fluid and their surface morphologies against immersion time.

关键词： titania hydroxyapatite composite film sol-gel route

Magnetic-porous microspheres with synergistic catalytic activity of small-sized gold nanoparticles and titania matrix

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Frontiers of Chemical Science and Engineering 2019年第3期13卷 574-585页

作者： Kadriye Ozlem Hamaloglu Ebru Sag Cigdem Kip Erhan Senlik Berna Saracoglu Kaya Ali Tuncel Hacettepe University Chemical Engineering DepartmentAnkaraTurkey Cumhuriyet University Chemical Engineering DepartmentSivasTurkey

Fe3O4 nanoparticles immobilized on porous titania in micron-size range were decorated with smallsized gold nanoparticles and used as a plasmonic catalyst for the reduction of 4-nitrophenol. Monodisperse-porous magnetic titania microspheres were synthesized with bimodal pore-size distribution by the sol-gel templating method. Small-sized gold nanoparticles obtained by the Martin method were attached onto the aminated form of the magnetic titania microspheres. A significant enhancement in the catalytic activity was observed using the gold nanoparticle-decorated magnetic titania microspheres compared to gold nanoparticle-decorated magnetic silica microspheres because of the synergistic effect between small-sized gold nanoparticles and titania. The synergistic effect for gold nanoparticle-attached magnetic titania microspheres could be explained by surface plasmon resonance-induced transfer of hot electrons from gold nanoparticles to the conduction band of titania. Using the proposed catalyst, 4-nitrophenol could be converted to 4-aminophenol in an aqueous solution within 0.5 min. The 4-nitrophenol reduction rates were 2.5-79.3 times higher than those obtained with similar plasmonic catalysts. The selection of micron-size, magnetic, and porous titania microspheres as a support material for the immobilization of small-sized gold nanoparticles provided a recoverable plasmonic catalyst with high reduction ability.

关键词： small-sized gold nanoparticles magnetic titania microspheres sol-gel template synthesis plasmonic catalysis 4-nitrophenol

Iron-Doped titania Nanoparticles for the Photocatalytic Oxidative Degradation of Nitrite

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Chemical Research in Chinese Universities 2001年第3期17卷 281-286页

作者： XU An-wu ZHU Jing-yan GAO Yuan LIU Han-qin School of Chemistry and Chemical Engineering Zhongshan UniversityGuangzhou 510275P.R.China

Iron-doped titania nanoparticles exhibit a higher photocatalytic activity than pure TiO_2 for the degradation of nitrite. The optimum Fe-doped content in terms of activity is approximately 0.5%. The increase in photoactivity is probably due to the higher adsorption and the inhibition of electron-hole recombination. The photocatalytic oxidation reaction of nitrite over the Fe-doped TiO_2 catalyst follows zero-order kinetics, which is different from that over pure TiO_2. The reaction rate decreases linearly with the increase of the pH of the solution.

关键词： Nitrite degradation Photocatalytic oxidation titania Iron doped

Preparation of nitrogen-doped titania and its photocatalytic activity

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Rare Metals 2007年第3期26卷 254-262页

作者： QIN Haoli GU Guobang LIU Song College of Chemistry South China University of Technology Guangzhou 510640 China School of Science Guizhou Normal University Guiyang 550001 China

Yellowish nitrogen-doped titania was produced through sol-gel method in mild condition, with the elemental nitrogen derived from aqua ammonia. The titania catalysts were characterized using XRD, BET, TEM, XPS, and UV-Vis diffuse reflectance spectrophotometer, and their photocatalytic activities were evaluated under UV and visible light, respec tively. The XRD results showed that all titania catalysts were anatase. More significantly, the crystallite size of nitrogen-doped titania increased with an increase in N/Ti proportion, and the doping of nitrogen could extend the absorption shoulder into the visible-light region, thus it possessed a higher visible-light activity illustrated by decolorization of methyl orange （65.3%） under the irradiation of visible light, whereas pure titania showed little of such kind of visible light activity. The UV-light activity of nitrogen-doped titania catalysts was worse than that of pure titania and Degussa P25. In the range of N/Ti proportion of 4-10 mol%, the activity of nitrogen-doped titania weakened appreciably in the visible-light region as the N/Ti proportion increased, whereas a reverse relationship existed under the irradiation of UV light.

关键词： photocatalysts titania nitrogen-doped methyl orange

Recovery of titania from high titanium slag by roasting method using concentrated sulfuric acid

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Rare Metals 2015年第12期34卷 895-900页

作者： Li-Li Sui Yu-Chun Zhai Li-Hua Miao Department of Chemistry Shenyang Medical College School of Materials and Metallurgy Northeastern University

By means of energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM) analysis, the phase structure characteristics of high titanium slag were analyzed. Through the single factor and the orthogonal experiment methods, the effects of material particle size, mass ratio of acid to ore, roasting temperature, and roasting time on the acidolysis ratio of TiO2 during the process of roasting high titanium slag with concentrated sulfuric acid were systematically investigated. The results show that the sequence of each factor affecting the acidolysis ratio of TiO2 is: mass ratio of acid to ore, roasting time, and roasting temperature. The optimum technological conditions are obtained as mass ratio of acid to ore of 2.1, roasting temperature of 310°C, roasting time of 75min, and material particle size of 45–53μm. The acidolysis ratio of TiO2 is over 96% under the optimum conditions. The roasting process is proved to be significant in the exploitation and utilization of high titanium slag. The advantages of the proposed roasting process are of high efficiency, low power consumption, and minimum pollution.

关键词： Concentrated sulfuric acid Roasting High titanium slag titania

Novel luminescent europium-centered hybrid material covalently grafted with organically modified titania via 2-substituted imidazophenanthroline for fluorescence sensing

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Journal of Rare Earths 2021年第6期39卷 666-673,I0002页

作者： Fenghan Wei Chao Bai Huai-Ming Hu Shi He Xiaofang Wang Ganglin Xue Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry and Materials ScienceNorthwestUniversityXi'an 710127China

By employing a rational approach,we prepared a novel kind of luminescent europium-centered hybrid material named Eu(tta)_(3)NCP-TiO_(2).The resulting material was characterized by FT-IR spectra,SEM,X-ray diffraction,thermogravimetric analysis,and photoluminescence spectra.The hybrid material features the combined advantages of the europium complex and the titania host,exhibiting not only good thermostability,but also long luminescence lifetime.Owing to the excellent luminescence of this material,the application in detecting organic small molecule solvents and metal ions was explored systematically.Significantly,Eu(tta)_(3)NCP-TiO_(2) exhibits superior detection for nitrobenzene molecule and Cu^(2+) ion in DMF(N,N-dimethylformamide) medium.Furthermore,the limit of detection(LOD) of Eu(tta)_(3)NCP-TiO_(2) for nitrobenzene and Cu^(2+) ion can be counted as 5.593× 10^(-5) and 9.566 ×10^(-5) mol/L,respectively.The results demonstrate that Eu(tta)_(3)NCP-TiO_(2) can serve as an efficient fluorescence probe for the detection of sensing of nitrobenzene and Cu^(2+) ion.

关键词： Hybrid material Ternary europium complex Imidazophenanthroline titania Fluorescence sensing Rare earths