Immobilization of nanoparticle titanium dioxide membrane on polyamide fabric by low temperature hydrothermal method

A thin layer of nanoparticle titanium dioxide was immobilized on polyamide 6 (PA6) fiber using titanium sulfate and urea at low temperature hydrothermal condition. The titanium dioxide loaded fabric was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and thermal gravimetry techniques. The optical and mechanical properties, water absorption and degradation of methylene blue dye under ultraviolet (UV) irradiation of the PA6 fabric before and after treatments were also examined. It was found that when PA6 fabric was treated in titanium sulfate and urea aqueous solution, anatase nanocrystalline titanium dioxide was synthesized and simultaneously adhered onto the fiber surface. The average crystal size of titanium dioxide nanoparticles was about 13.2 nm. The thermal behavior of PA6 fiber distinctly changed and the onset decomposition temperature decreased. As compared with the untreated fabric, the protection against UV radiation was improved. The water absorbency increased slightly. As the fabric dimensions were reduced in warp and weft directions, the breaking load and tensile strain increased to some extent. The titanium dioxide coated fabric could degradate methylene blue dye under UV irradiation.     

Photocatalytic reduction of NO with NH3 using Si-doped TiO2 prepared by hydrothermal method

A series of Si-doped TiO2 (Si/TiO2) photocatalysts supported on woven glass fabric were prepared by hydrothermal method for photocatalytic reduction of NO with NH3. The photocatalytic activity tests were carried out in a continuous Pyrex reactor with the flow rate of 2000mL/min under UV irradiation (luminous flux: 1.1x10(4)lm, irradiated catalyst area: 160cm2). The photocatalysts were characterized by X-ray diffraction (XRD), BET, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectrophotometer, transmission electron microscopy (TEM), photoluminescence (PL) and temperature-programmed desorption (TPD). The experiment results showed that NO conversion on Si/TiO2 at 323K could exceed 60%, which was about 50% higher than that on Degussa P25 and pure TiO2. With the doping of Si, photocatalysts with smaller crystal size, larger surface area and larger pore volume were obtained. It was also found that Ti-O-Si bands were formed on the surface of Si/TiO2 and that the surface hydroxyl concentration was greatly increased. As a result, total acidity and NH3 chemisorption amount were enhanced for Si/TiO2 leading to its photocatalytic activity improvement.     

Effect of nickel oxide seed layers on annealed-amorphous titanium oxide thin films prepared using plasma-enhanced chemical vapor deposition

The effect of a nickel oxide (NiO_x) seed layer on the crystallization and photocatalytic activity of the sequentially plasma-enhanced chemical vapor deposited amorphous titanium oxide (TiO_x) thin film processed by a post-annealing process was investigated. The evolution of the crystalline structures, chemical bond configurations, and surface/cross-sectional morphologies of the annealed TiO_x films, with and without a NiO_x seed layer, was examined using X-ray diffractometer, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, atomic force microscopy, and field emission scanning electron microscope measurements. Thermo- and photo-induced hydrophilicity was determined by measuring the contact angle of water droplet. Photocatalytic activity after UV light irradiation was evaluated from the decolorization of a methylene blue solution. The crystallization temperature of the TiO_x film, deposited on a NiO_x seed layer, was found to be lower than that of a pure TiO_x film, further improving the thermo- and photo-induced surface super-hydrophilicity. The TiO_x film deposited onto the NiO_x seed layer, resulting in significant cluster boundaries, showed a rough surface morphology and proved to alleviate the anatase crystal growth by increasing the post-annealing temperature, which yielded a more active surface area and prohibited the recombination of photogenerated electrons and holes. The photocatalytic activity of the NiO_x/TiO_x system with such a textured surface therefore was enhanced and optimized through an adequate post-annealing process.     

表面包覆CeO2制备高耐候性钛白的研究

在金红石TiO2水性分散体浆料中,保持温度为70℃,PH值为9.5,分别加入TiO2基料的1%、0.2%、0.05%的硝酸铈溶液(w,以CeO2计)进行CeO2包膜,获得了光催化活性分别为0、0.13、0.47的高耐候性TiO2颜料.ξ电位测定表明,TiO2单分散的最佳条件是pH=9.5～10.5.热力学分析表明,CeO2在TiO2颗粒表面形核时的自由能ΔGh较小,CeO2可以顺利包覆于TiO2颗粒表面.     

Photocatalytic activity of manganese, chromium and cobalt-doped anatase titanium dioxide nanoporous electrodes produced by re-anodization method

Transition metal-doped TiO₂ electrodes were prepared by re-anodization and characterized. The structure of these electrodes was investigated by X-ray diffraction and electron diffraction, which mainly showed typical characteristic anatase reflections without any dopant-related peaks. The amount of transition metal dopant in TiO₂ was kept at approximately 1.0 at.%, as measured by energy dispersive X-ray spectroscopy. The effects of different types of dopants on the photocatalytic activity were revealed by measuring the degradation of an organic aqueous solution containing a dye (acid red G) using a combination of ultraviolet (UV) light energy in the presence of these electrodes. The photocatalytic efficiency was remarkably enhanced by the incorporation of Mn ²⁺ and Cr³⁺. Mn²⁺ showed the most significant enhancement. However, Co²⁺ accelerated the rate of acid red G degradation only slightly. Langmuir-Hinshelwood rate expression was employed for the degradation of acid red G by UV/TiO₂ electrodes system. The adsorption equilibrium constant, the rate constant, and the initial degradation rate were determined for different electrodes. The effect of the concentration of Mn²⁺ on the degradation of acid red G was also investigated and the results showed that there is an optimal value (about 1.0 at.%) of the concentration of Mn²⁺ for inducing faster degradation of the dye. The enhanced photocatalytic degradation rate of acid red G in the presence of transition metals is attributed to the increase of the charge separation in these systems.     

Determination of trace lead in water samples by graphite furnace atomic absorption spectrometry after preconcentration with nanometer titanium dioxide immobilized on silica gel

Nanometer titanium dioxide immobilized on silica gel (immobilized nanometer TiO2) was prepared by sol-gel method and characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorptive capability of immobilized nanometer TiO2 for lead was assessed in this work using column method. It was found that lead can be quantitatively retained by immobilized nanometer TiO2 in the pH range 4-7, then eluted completely with 1.0molL(-1) HCl. The adsorption capacity of immobilized nanometer TiO2 for Pb was found to be 3.16mgg(-1). A new method has been developed for the determination of trace lead based on preconcentration with a microcolumn packed with immobilized nanometer TiO2 prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS). The detection limit of this method for Pb was 9.5ngL(-1) with an enrichment factor of 50, and the relative standard deviations (R.S.D.s) was 3.2% at the 10ngmL(-1) Pb level. The method was validated using a certified reference material, and was applied for the determination of trace lead in water samples.     

Photocatalytic behavior of different titanium dioxide layers

Many recently developed applications are related to the photocatalytic behavior of semiconductive oxides. Among the different oxides, titanium dioxide (TiO₂) is one of the most interesting due to its high photocatalytic efficiency towards a great number of reactions and to its hydrophilic properties. Aim of this work is the evaluation and comparison of the photocatalytic properties of different crystalline titanium dioxide films, directly grown on titanium substrates by surface anodization (eventually followed by thermal annealing) and by Pulsed Laser Deposition (PLD) on titanium and silicon substrates, followed by thermal annealing. The structure and morphology of the layers were characterized by Scanning Electron Microscopy and X-Ray Diffraction and photocatalytic tests on stearic acid mineralization were performed. Results showed that the PLD layers possess a higher photocatalytic efficiency than anodized titanium. This can be attributed to the microstructured/microporous morphology of the related surfaces. Instead, PLD TiO₂ layers with a relatively high content of the rutile phase have a reduced photocatalytic efficiency with respect to mainly anatase containing layers.     

纳米TiO2的原位包覆及分散性研究

采用水热合成法制备纳米TiO2粉体,以自制的1100分散剂对粉体进行原位包覆和后包覆,考察了分散剂用量、pH值对包覆体系分散性的影响,利用XRD和TEM进行结构表征和形貌观测,并采用分光光度法对纳米TiO2粉体水分散体系稳定性进行了检测,在此基础上制备了纳米TiO2／有机复合涂膜．研究表明：原位包覆制备的纳米TiO2中,锐铁矿相的质量分数为100％,分散较均匀,纳米TiO2粉体的平均粒径约为20nm;分散剂用量为8．0％、pH值为3和10时,其水溶液分散稳定性较高;后包覆制备的纳米TiO2粉体由锐钛矿相（73％）和金红石相（27％）构成,纳米TiO2粒子处于团聚状态,无明显颗粒形态;涂膜经自然光照射24h后,对大肠杆菌的杀灭率为99．8％;良好的分散工艺和有效的分散剂可充分发挥纳米TiO2的光催化功能．     

Photocatalytic removal of hazardous dye cyanosine from industrial waste using titanium dioxide

In this paper, photocatalytic degradation studies of a hazardous water soluble xanthene dye cyanosine in aqueous suspensions of titanium dioxide under a variety of conditions, viz., catalyst concentration, substrate concentration, pH, temperature and electron acceptor hydrogen peroxide (H2O2) have been reported. It was observed that photocatalytic degradation by TiO2 is an effective, economic and faster mode of removing cyanosine from aqueous solution. The optimum conditions for the degradation of the dye was dye concentration 1x10(-4)M, pH 8, catalyst concentration 0.04g/L and temperature +/-30 degrees C. Chemical oxygen demand and dye absorbance of the photodegraded dye solution substantially decreased.     

微波法制备具有可见光活性的氮掺杂二氧化钛

采用乙二醇作为溶剂，脲为氮源，用微波法制备了氮掺杂的二氧化钛纳米催化剂。采用傅立叶变换红外（FTIR），波长色散谱（WDS），X射线衍射（XRD），X射线光电子能谱（XPS）等对样品的化学组成以及表面基团进行了表征和分析。在模拟太阳光和可见光的条件下对甲基橙进行光催化降解评价，结果表明该催化剂在没有降低二氧化钛紫外区活性的同时具有较高可见光催化活性。     

钛氧膜生物相容性与生物活性的研究与应用

对钛氧膜的生物相容性和生物活性的研究及应用进行了评述.重点讨论了钛氧膜的制备方法、钛氧膜的活化处理方式以及钛氧膜在心血管材料和骨替代材料中的应用前景.     

Surface characterization of titanium oxide films synthesized by ion beam enhanced deposition

In this article, titanium oxide films were prepared by ion beam enhanced deposition where titanium was evaporated by electron beam and simultaneously bombarded with xenon ion beams at an energy of 40 keV in an O₂ environment. X-ray photoelectron spectroscopy and Auger electron spectroscopy were used to research the chemical state and composition of the titanium oxide films. The results show that surface of the film was fully oxidized. After the surface was removed by argon ion sputtering, the results show that Ti²⁺, Ti³⁺ and Ti⁴⁺ states exist on the sputtered surface. The atomic concentration of all the three titanium states were calculated. The chemical shift of O 1s peak was also observed on the near surface.     

TiO_2和活性炭纤维复合物光催化降解亚甲基蓝

以粘胶基活性炭纤维(VACF)为基体,钛酸丁酯为前驱体,通过溶胶-凝胶浸渍涂覆法将二氧化钛(TiO2)负载于粘胶基活性炭纤维上,制备活性炭纤维负载的TiO2光催化复合物,通过控制活性炭纤维在溶胶中的浸泡时间,制得不同TiO2负载量的复合物。采用扫描电子显微镜(SEM)表征了制备材料的形态结构,以质量浓度为20mg/L的亚甲基蓝溶液为目标降解物,测试了材料在紫外线光照下的催化性能。结果表明:紫外光直接照射对亚甲基蓝基本无降解作用,对活性炭纤维原样有一定作用;随着TiO2负载量的增加,复合物的吸附性能得到提高,对亚甲基蓝的降解作用也得到增强。     

Hydrothermal synthesis of highly pure brookite-type titanium oxide powder from aqueous sols of titanate nanosheets

Hydrothermal synthesis of brookite-type titanium dioxide was examined using aqueous sols of titanate nanosheets, which were prepared with Ti[OCH(CH₃)₂]₄ and N(CH₃)₄OH by a bottom-up process in aqueous solutions. Highly pure brookite powders were yielded at hydrothermal temperatures as low as 120 °C and N(CH₃)₄OH/Ti[OCH(CH₃)₂]₄ molar ratios greater than 2. Although titanate nanosheets are formed at N(CH₃)₄OH/Ti[OCH(CH₃)₂]₄ ≥ 0.4, the addition of excess N(CH₃)₄OH was critical in forming highly pure brookite powders. Excess N(CH₃)₄⁺ caused the precipitation of layered titanates, which were formed by stacking titanate nanosheets. Additionally, the crystal nucleation of brookite occurred in the precipitates. Then, the adsorption of titanate nanosheets on brookite particles caused the particles to transform into rod-like shapes elongated along the c-axis. The adsorbed titanate nanosheets were structurally converted into brookite under the influence of the underlying brookite crystal. Despite having a rough surface, the resulting brookite particles were single crystal-like. Moreover, the use of any tetraalkylammonium hydroxides other than N(CH₃)₄OH did not yield brookite. The addition of N(CH₃)₄OH to the reaction sols yielded precipitates of small titanate nanosheets. The morphology of the titanate nanosheets could have a significant influence on brookite crystallization.     

The photocatalytic properties of bismuth oxide films prepared through the sol-gel method

In this research, thin bismuth oxide films were prepared through the sol-gel method. In order to study the influence of bismuth oxide crystal phases on the photocatalytic properties of bismuth oxide films, these films were annealed at different temperatures and then applied to decompose a typical textile industry pollutant (Rhodamine B). Scanning electron microscopy, X-ray diffraction and profilometry were applied to characterize these films. It has been found that different annealing temperatures cause the transformation of different bismuth oxide crystal phases, which leads to the different removals of Rhodamine B photolyzed using bismuth oxide films as photocatalyst.     

Structural and photoluminescence properties of aligned Sb-doped ZnO nanocolumns synthesized by the hydrothermal method

Aligned Sb-doped ZnO nanocolumns were synthesized by a simple hydrothermal method. Based on the analyses of the X-ray diffraction and photoluminescence result, it could be confirmed that the Sb has successfully doped in the ZnO crystal lattices to form an accepter energy level. At 85 K, the recombination of the acceptor-bound exciton was predominant in PL spectrum, which was attributed to the transition of the (Sb_Zn-2V_Zn) complex bound exciton. The acceptor binding energy had been calculated to be 123 meV.     

银离子掺杂TiO2薄膜的物理性能研究

不同剂量的银离子被注入到采用反应磁控溅射(RMS)制备出的TiO2薄膜中.实验发现,薄膜的成分以二氧化钛和单质银为主,薄膜中可以看到银的纳米晶颗粒.注入的银离子在薄膜中呈近高斯分布,分布峰随注入剂量的增加而向表层移动.银离子注入后原本致密平整的TiO2薄膜表面出现了沟壑和晶粒粗化现象,且均方根粗糙度随注入剂量的增加而增加.不同的注入剂量对薄膜的表面能没有明显的影响.     

Increasing photoactivity of titanium dioxide immobilized on glass plate with optimization of heat attachment method parameters

In the present work the optimization of heat attachment method for increasing photoactivity of immobilized TiO₂ on glass plate was investigated. Results show that sonication time, TiO₂ suspension dosage, immobilization temperature, solvent type and immobilization replications are very effective on the photoactivity of immobilized TiO₂ on glass plate on the removal of C.I. Acid Red 88 (AR88) and optimizing these parameters increases the photoactivity of immobilized catalyst. In other step, the effect of operational parameters such as light intensity and initial concentration of AR88 on the removal of AR88 was investigated with four times immobilized TiO₂ on glass plate. Results show that removal rate decreases with increasing initial concentration of AR88 but increases with increasing UV-light intensity.     

Nonlinear optical response of titanium oxide nanostructured thin films

Titanium (IV) oxide thin films prepared by low temperature (95 °C) hydrothermal growth were observed to undergo important structural modifications upon variation of the deposition period, modifications strongly affecting the nonlinear optical (NLO) response of the films. Depending on the growth time, the films were observed to contain anatase or rutile TiO₂. It was found that only anatase TiO₂ exhibits significant nonlinear optical response.     

氧化钛薄膜表面等离子体处理引发官能团形成的研究

采用水/氧气,丙烯酸/氧气脉冲射频等离子体处理方法,对氧化钛薄膜进行表面改性.结果表明,水蒸气/氧气混合气体等离子体处理在氧化钛薄膜表面产生了吸附水及游离羟基,丙烯酸/氧气混合气体等离子体处理在氧化钛薄膜表面形成了羟基、羧基和羰基官能团.经水蒸气/氧气、丙烯酸/等离子体处理的氧化钛薄膜的水接触角分别降低了67.3和58.5°,极性分量分别增加了36.5和50.9mJ/m2,表现出很好的亲水性.