Preparation of High-Orderly TiO2 Nanotubes in Organic Solution and Characterization of C-doped TiO2

"High-orderly TiO2 nanotube arrays were fabricated by anodic oxidation of pure titanium substrate in organic electrolyte containing fluoride. Different morphological nanotubes of titania were obtained through controlling the different anodization voltages and durations. The length of the longest nanotubes was approximately 60 1m and the length-to-width aspect ratio was about 600. The nanotube layers were then annealed at different temperatures (450, 550, and 650 oC) in air for 2 h. The samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), energy dispersive X-Ray (EDS) and UV-Vis spectrometer. The XRD results demonstrated that the as-anodized samples were amorphous and the structure changed to antanse and rutile when the samples were annealed at higher temperature. The EDS microanalysis indicated the presence of carbon in the TiO2 nanotubes. The result of degradation of methylene blue showed clearly that the photocatalytic activity of C-doped TiO2 nanotubes increased by 10%."     

水热法制备掺杂铁离子的TiO2纳米粒子及其光催化反应研究

以TiCl⁴为前驱体,采用水热法制备了掺杂铁离子的TiO₂纳米粒子,利用XRD对不同条件下制备的产物进行了表征,探讨了反应温度、胶体溶液pH值和反应时间对水热反应的影响.考察了所制备的Fe³⁺-TiO₂纳米粒子光催化降解罗丹明B的催化性能,实验发现,制备的掺杂0.1%Fe³⁺-TiO₂纳米粒子与纯TiO₂相比,具有更好的催化活性.     

La2O3掺杂TiO2光催化剂的制备和性能

采用溶胶-凝胶法制备了La2O3掺杂TiO2纳米光催化剂，并通过XRD、TEM、BET和XPS等手段进行了表征．掺入La2O3后，阻止了TiO2从锐钛矿晶型向金红石晶型的转变，使TiO2的粒径减小，比表面积增大．以甲基橙为光催化降解反应模型化合物，考察了光催化剂的活性．测定了甲基橙在纯TiO2和La2O3掺杂TiO2光催化剂上的吸附常数．考察了pH、H2O2对降解性能的影响．讨论了光催化活性与催化剂性质的关系．     

A novel Fe（OH）3/TiO2 nanoparticles and its high photocatalytic activity

A very simple and controllable approach was proposed to synthesize novel Fe(OH)_3/TiO_2 nanoparticles.Compared with neat TiO2,the Fe(OH)_3/TiO_2 increased the rate of the photocatalytic degradation of methyl orange at pH 6.0 by more than five times, showing photocatalytic activity as excellent as P25.This enhancing effect is mainly attributed to the ferric hydroxide deposits as the electron scavenger and the enriched surface hydroxyl groups.     

活性炭负载Cu离子掺杂纳米TiO2颗粒的制备及光催化性能

采用溶胶-凝胶法在活性炭(AC)表面负载掺杂Cu离子的TiO2纳米颗粒, 制备负载型掺杂Cu2+-TiO2/AC复合光催化剂, 采用XRD, ESR, FS, UV-Vis和BET等手段对其进行了表征, 通过罗丹明B的光催化降解试验, 分析活性炭载体的比表面积和Cu离子掺杂量对负载型掺杂催化剂光催化活性的影响. 结果表明, Cu以+2价存在, Ti以少量的+3价存在; TiO2纳米颗粒具有量子尺寸效应, 吸光阈值显著蓝移, 并使光谱相应范围向可见光区拓展; 另外, 适量Cu离子的掺杂降低了负载型TiO2/AC的荧光强度. 负载和高温处理没有改变活性炭载体的微观结构. 以AC3为载体和质量分数为3%的Cu离子掺杂所制备的3%Cu2+-TiO2/AC3催化剂的活性最高, 并且该催化剂便于回收, 在重复使用中也表现出很高的光催化活性.     

CNT/Fe-Ni/TiO_2/ZnO阵列修饰Ni阳极的制备及光催化制氢性能

采用层层自组装方法在Ni片阳极上构建TiO2/Zn O纳米棒阵列,以二氧化钛前驱体溶胶中掺杂的铁和镍为催化剂,通过气相沉积法在TiO2/Zn O纳米棒阵列间原位生长碳纳米管(CNTs),得到CNT/Fe-Ni/TiO2/Zn O复合光催化剂修饰的光活性Ni片阳极.以碱性电解池为基础,用紫外线辐照修饰的Ni阳极实现光催化和电解水的有机耦合制氢过程.通过场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、拉曼光谱(Raman)和电化学阻抗谱(EIS)对CNT/Fe-Ni/TiO2/Zn O复合膜光催化剂的结构进行了表征,并测试了其光催化辅助电解水制氢(WEAP)活性.结果表明,生长了碳纳米管的光催化复合膜CNT/Fe-Ni/TiO2/Zn O修饰的Ni阳极的产氢速率分别比Fe-Ni/TiO2/Zn O修饰的Ni阳极和纯Ni片提高了93.7%和533.0%.     

Removal of La(III) by amino-phosphonic acid functionalized polystyrene microspheres prepared via electron beam irradiation

A new aminophosphonic acid chelating resin was successfully prepared via electron beam irradiation grafting combined with chemical modification and used for the efficient removal of La(III). Firstly, glycidyl methacrylate (GMA) was grafted to polystyrene microspheres (PS) via electron beam co-radiation to obtain PS-PGMA microspheres, then followed by the amination with diethylenetriamine (DETA) to formed PS-PGMA-DETA (PGD) microspheres through nucleophilic substitution between amino and epoxy group, and finally PS-PGMA-DETA-PA (PGDP) microspheres was obtained by phosphorylation with phosphorous acid (PA). The obtained chelating resin absorbent was characterized by Fourier-transform infrared (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), which demonstrated that the millimetric aminophosphonic acid chelating resin were successfully prepared with well-defined morphology and enhanced thermal stability. The X-ray photoelectron spectroscopy (XPS) characterization results confirmed a possible adsorption mechanism, which is mainly based on the chelation and coordination of N and O in PDGP with La(III) in the solution. A series of parameters were taken into account in the adsorption experiment, such as absorbed dose, GMA concentration, dosage of PGDP, pH, contact time, temperature, and the initial concentrations of La(III). The maximum adsorption capacity obtained from the research can be achieved 288.69 mg/g at 298.15 K, pH = 6. The kinetic sorption for for La(III) fitted the type 1 pseudo-second-order (R² = 0.9981), which revealed that the La(III) are chemisorbed on the surface of the PGDP. It was concluded that the La(III) adsorption conformed to the Freundlich equation, indicating a multilayer adsorption process. Thermodynamic data indicated that the La(III) uptake process was a spontaneous and endothermic. In addition, this research provided a new irradiation grafting method for rare earth ions removal.     

Heterogeneous Photocatalytic Degradation of Disulfoton in Aqueous TiO2 Suspensions: Parameter and Reaction Pathway Investigations

The photocatalytic degradation of organophosphorus insecticide disulfoton is investigated by having titanium dioxide (TiO₂) as a photocatalyst. About 99% of disulfoton is degraded after UV irradiation for 90 min. The effects of the solution pH, catalyst dosage, light intensity, and inorganic ions on the photocatalytic degradation of disulfoton are also investigated, as well as the reaction intermediates which are formed during the treatment. Eight intermediates have been identified and characterized through a mass spectra analysis, giving insight into the early steps of the degradation process. To the best of our knowledge, this is the first study reporting the degradation pathways of disulfoton. The results suggest that possible transformation pathways may involve in either direct electron or hole transfer to the organic substrate. The photodegradation of disulfoton by UV/TiO₂ exhibits pseudo‐first‐order reaction kinetics and a reaction quantum yield of 0.267. The electrical energy consumption per order of magnitude for photocatalytic degradation of disulfoton is 85 kWh/(m³ order).     

In situ polypyrrole polymerization enhances the photocatalytic activity of nanofibrous TiO2/SiO2 membranes

PPy@TS nanocomposite with enhanced photocatalytic capability was prepared by in situ polymerizing polypyrrole on the surface of TiO₂/SiO₂ nanofibrous membrane.     

形态结构和光电特性对纳米TiO2光催化性能的影响

采用sol-gel法制备了系列纳米TiO2光催化剂,运用X射线衍射、BET比表面测定、紫外漫反射吸收光谱和表面光电压谱等手段对催化剂进行表征,并以乙烯作为光催化反应的指标反应分子,研究了TiO2纳米晶的性质对于光催化活性的影响.随着焙烧温度的升高,TiO2的晶粒逐渐增大,比表面积下降,晶相由锐钛矿向金红石转变,其吸收带边与光伏响应阈值向长波方向移动,氧化－还原能力降低,降解乙烯的转化率迅速下降.     

苯乙酮的TiO2光催化降解及其影响因素

在TiO2(Degussa P25)和波长大于350 nm的光作用下,水中苯乙酮(1×10-5～1×10-4mol／L)能发生光催化降解,生成邻羟基苯乙酮等中间产物.该降解过程遵循Langmuir-Hinshelwood动力学方程,降解速率随入射光强度的增强和溶液起始pH值的增大而增大,但反应温度的影响较小,其降解反应的表观活化能为4.2～6.4 KJ/mol.     

TiO2光催化降解苯和甲苯的动力学研究

利用溶胶-凝胶法制备了粒径约为13nm、晶型为锐钛矿相和金红石相混晶的TiO2光催化剂,并利用此催化剂对挥发性有机污染物苯和甲苯进行了光催化降解研究,对不同的催化剂用量、光源、污染物的初始浓度以及氧气对光催化反应速率的影响进行了研究。结果表明,光催化降解甲苯和苯的反应均符合假一级动力学方程,光强与光催化降解甲苯的反应的速率常数之间呈指数关系,光波长对光催化降解苯的影响也很显著;随着甲苯和苯初始浓度的增加,光催化反应速率常数降低;氧气加快了光催化降解甲苯和苯的速率;对于光催化降解初始浓度为37.6μmol/L的甲苯而言,催化剂的最佳使用量为0.30g,对于光催化降解初始浓度为9.0μmol/L的苯来说,催化剂的最佳用量为0.10g。     

Facile Preparation and Visible-light Photocatalysis Enhancement of N-Doped β-TiO2 Nanobelts

A facile preparation of nitrogen-doped β-TiO₂(N-doped β-TiO₂) nanobelts and their visible-light photocatalytic activity were reported. The preparation of N-doped β-TiO₂ nanobelts consisted of cation-exchange between layered sodium titanate nanobelts and NH₄⁺ in aqueous solution at room temperature and subsequent calcination in air. Such a calcination treatment is beneficial to the formation of monoclinic N-doped β-TiO₂ nanobelts. Various measurement results indicate that not only were the nitrogen atoms doped into the lattice of β-TiO₂ nanobelts resulting in a strong visible-light absorption, but also a large number of defects were caused by them in the lattice, increasing the stability of β-TiO₂. The photocatalysis enhancement of N-doped β-TiO₂ nanobelts for the photodegradation of Rhodamine B was demonstrated.     

高温氮掺杂制备二氧化钛导电粉

以廉价的偏钛酸为原料,在高温下进行N掺杂,制备了具有良好导电性能的TiO2粉,950℃焙烧3h后,体积电阻率低达6.5×10-3Ω.cm。高浓度N的受主掺杂在TiO2禁带中形成连续的能级,在紫外可见范围内都有很强的光吸收性能,电阻率随N含量的增加而下降。采用XRD、XPS、元素分析、紫外-可见漫反射、扫描电镜分析了粉体的晶相组成、元素价态、N含量、表面形态和粒径大小。     

Preparation of Near IR Reflective Materials via Hollow Ballotini Enwrapped by TiO2

Near IR reflective materials have many applications in the realm of aviation and spaceflight, architectural material, automobile and weaponry et al. In this work, a new preparation process, which metatitanic acid deposited on the surface of hollow balloti…     

Influence of carbon source on the anatase and brookite mixed phase of the C-doped TiO2 nanoparticles and their photocatalytic activity

Choosing resorcinol, phloroglucinol, ethylene glycol and glycerol as carbon sources, respectively, C-doped TiO₂ nanoparticles are prepared via hydrothermal method. Here glucose is first used to determine the optimal C-doping amount and reaction environment. The experimental results reveal that adding small amount of carbon in TiO₂ can change the phase structure of the TiO₂, the self-characteristic of carbon source influences the ratio of anatase to brookite in the mixed phase structures, and the carbon source with no benzene ring can lead to a high content of brookite phase. The mixed crystal phases show lower band gap energy and less photogenerated electronic-hole recombination. Furthermore, a high content of hydroxyls in carbon source and a high ratio of brookite phase in the mixed crystal phases are beneficial to the photocatalytic performance.     

Eu／TiO2光催化降解部分水解聚丙烯酰胺影响因素研究

考查了以四异氧丙基钛(TTIP)为钛源,采用溶胶-凝胶的合成方法制备Eu掺杂TiO2纳米晶催化剂.运用X射线粉体衍射光谱仪(XRD)检测到制备的复合物具有锐钛矿晶型、透射电镜(TEM)和N2吸附表征催化剂的形貌和吸附特性:Eu/TiO2纳米晶粒子分散均匀,平均粒径为9 nm左右.比表面积107 m2/g,孔体积0.5 cm3/g、孔径14.0 nm.此外,研究了在紫外光作用下催化条件对光催化降解部分水解聚丙烯酰胺的影响,如:光催化时间、催化剂的浓度、HAPM的初始浓度、反应的pH值及Na2CO3,NaHCO3和NaCl浓度对催化的影响.结果表明,除NaCl外,其它条件对HPAM的催化降解均有显著的影响.增加催化时间、最佳的催化剂浓度、pH~6和较低的初始浓度有利于催化反应的进行.     

Species,engineering and characterizations of defects in TiO2-based photocatalyst

This review gave a brief summary on the main species, engineering and characterizations of defects on the TiO₂-realted model photocatalyst.     

纳米SnO2／TiO2的制备及光催化臭氧化活性

用沉积-沉淀法制备了一系列不同Sn/Ti比例的纳米催化剂SnO2/TiO2, 以糖蜜酒精废水的脱色降解为探针反应, 研究了在紫外光条件下Sn/Ti比和焙烧温度对其臭氧化活性的影响. 结果表明, 在Sn掺杂量为5%(mol)时, 焙烧温度773K时, SnO2/TiO2催化活性最好. XRD、TPR显示, 部分Sn4+可能掺入到TiO2的晶格之中, 形成了Sn-O-Ti键. 紫外漫反射光谱显示, 复合SnO2/TiO2对光的吸收明显增加, 催化活性的提高应归因于SnO2/TiO2表面的臭氧吸附. SnO2/TiO2光催化臭氧化降解糖蜜酒精废水的活性与臭氧在催化剂表面的吸附分解有很大的关系, 光的作用只是强化催化臭氧化的氧化效果.     

Photoelectrochemical oxidation behavior of organic substances on TiO2 thin-film electrodes

The photoelectrocatalytic oxidation characteristics of salicylic acid, formic acid and methanol on anodized nanoporous titanium dioxide (TiO₂) thin-films were investigated by using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. From dark to ultraviolet illumination, the open circuit potential (OCP) and film resistance of TiO₂ films decreased markedly. A general equivalent circuit model was proposed for the photoelectrochemical system anodic TiO₂ thin-film electrode/test solution. The photoelectrochemical oxidation process of the organic compounds showed similar impedance features at OCP and was controlled by the charge transfer step. According to the polarization curves of the base solution and organic solutions, the kinetic rate curves for the photoelectrocatalytic oxidation of pure organic species were obtained as a function of the potential bias. One photooxidation peak was first observed at a bias potential of ca. 0.26 V for these species with low concentrations.