Ordered mesoporous Fe/TiO_2 with light enhanced photo-Fenton activity

Ordered mesoporous Fe/TiO2 was prepared by an evaporation-induced self-assembly method. The iron ions were in situ embedded in the pore wall of the TiO2 framework. The catalyst has excellent light-assisted Fenton catalytic performance under UV and visible light irradiation. X-ray diffraction and transmission electron microscopy results showed that the TiO2 samples have an ordered two-dimensional hexagonal pore structure and an anatase phase structure with high crystallinity. The ordered pore structure of the TiO2 photocatalyst with a large specific surface area is beneficial to mass transfer and light harvesting. Furthermore, iron ions can be controlled by embedding them into the TiO2 framework to prevent iron ion loss and inactivation. After five cycles, the reaction rate of the ordered mesoporous Fe/TiO2 remained unchanged, indicating that the material has stable performance and broad application prospects for the purification of environmental pollutants.

One-step fabrication of TiO2/graphene hybrid mesoporous film with enhanced photocatalytic activity and photovoltaic performance

We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.

Photocatalytic degradation of formaldehyde using mesoporous TiO_2 prepared by evaporation-induced self-assembly

The mesoporous Ti O2 has been synthesized by evaporation induced self assembly(EISA) method. The thermogravimetric/differential scanning calorimetric(TG/DSC), X-ray diffraction(XRD), high-resolution transmission electron microscopy(HR-TEM) and N2 adsorption desorption and adsorption are used to study the effects of the synthesized process condition on the microstructure of the as-synthesized mesoporous Ti O2. The photocatalytic performances of as-synthesized samples are evaluated by the degradation of the formaldehyde under ultraviolet light irradiations. The results demonstrate that the as-synthesized mesoporous Ti O2 are anatase with the uniform size about 20-40 nm. The sample is prepared using cetyltrimethyl ammonium bromide(CTAB) as the template with average pore size distribution of 8.12 nm, specific surface area of 68.47 m2/g and pore volume of 0.213 m L/g. The samples show decomposition of formaldehyde 95.8% under ultraviolet light irradiations for 90 min. These results provide a basic experimental process for preparation mesoporous Ti O2, which will posses a broad prospect in terms of the applications in improving indoor air quality.

Synthesis and Characterization of TiO₂Porous Films for Heterogeneous Photocatalysis

Heterogeneous photocatalysis is one of the advanced oxidation processes (AOP’s). These are very used nowadays for their implementation in tertiary water treatment with solar activation, with very good results. In this study, TiO2 porous films were synthesized by sol-gel method. Polyethylene glycol (PEG) 4000 was used as a templating reagent, which is oxidized at a lower temperature than TiO2. This allows the formation of a “skeleton” of porous TiO2 with increased surface area, resulting in higher photocatalytic activity. The film characterization was made with help of FE-SEM microscope, XRD diffractometer and scotch tape test. Finally, the oxidation experiments were performed using methylene blue as a model pollutant and they revealed an increase in the photocatalytic activity of porous films in comparison with the non-porous films.

以PVP为软模板构建的层状介孔TiO_(2)及其光催化性能

以聚乙烯吡咯烷酮(PVP)为软模板、硫酸钛为钛源,采用无机沉淀-胶溶法制备了层状介孔PVP-TiO_(2)。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、紫外可见吸收光谱(UV-Vis-Abs)、比表面积分析仪(BET)分别对样品的表面形貌、晶相组成、紫外吸收带边、比表面积和孔结构进行了表征分析,对层状结构的形成机理进行了研究。以甲基橙为目标降解物,研究了样品的光催化性能。结果表明:在相同条件下,PVP-TiO_(2)对甲基橙的最佳降解率达到93.84%,明显高于纯TiO_(2)。经PVP改性后,TiO_(2)试样出现了层状介孔结构,结晶度和晶粒尺寸均减小,促进了锐钛矿向金红石相的转变,并且PVP的引入使得TiO_(2)的光吸收带边发生了一定的蓝移。

TiO_2/Pt/glass纳米薄膜的制备及对可溶性染料的光电催化降解

ＴｉＯ２／Ｐｔ／ｇｌａｓ纳米薄膜的制备及对可溶性染料的光电催化降解符小荣＊张校刚＊＊宋世庚王学燕谭辉陶明德（中国科学院新疆物理研究所乌鲁木齐８３００１１，＊＊新疆大学化学系乌鲁木齐）关键词光催化，ＴｉＯ２，光电化学，薄膜，溶胶－凝胶法１９９６－０９－...

掺铁TiO_2用于NO_2^-光催化降解研究

采用溶胶 凝胶法制备了掺杂铁的TiO2 粉末 ,并用XRD、SEM、UV Vis漫反射光谱等技术手段考察了掺入铁TiO2 粒子形态的变化 ,以及掺杂与否对氧化降解NO-2 的影响 .研究结果表明 ,铁的掺入可影响TiO2 的结构相变及粒子大小 ,并且发现掺杂后TiO2 对NO-2 的氧化活性显著提高 ,在掺杂量 3 0 %时具有最佳活性 .

可见光响应的LaVO_4/TiO_2纳米管的合成、表征及对气相甲苯的光催化性能

通过水热方法合成了可见光响应的LaVO4/TiO2纳米管,采用XRD,TEM,氮气吸附-脱附以及表面光电压谱对样品进行了表征.以气相甲苯为典型污染物,研究了制备样品在可见光(λ>420 nm)条件下的光催化性能.实验结果表明,LaVO4的复合使TiO2的粒径减小,比表面积增大,光响应范围向可见光偏移.光催化实验结果表明,在可见光条件下,LaVO4/TiO2纳米管降解甲苯的效率比其它样品高,与纯TiO2纳米管相比,降解效率提高了47%.

复合材料TiO2/MoS2的制备及对油田废水处理

以钛酸丁酯和钼酸铵为前驱体,采用溶胶-凝胶法和水热法分别制备TiO 2、MoS 2和TiO 2/MoS 2纳米材料,并通过FTIR、XRD、SEM、DRS和BET等手段表征其结构、组成、形貌和孔径大小。以油田废水为光催化降解反应模型,考察了光催化活性,测定了催化剂的容量、反应条件如投加量、pH值、反应时间等因素。处理废水为200 mL,TiO 2、TiO 2/MoS 2投加量为0.8 g,pH=3~4,反应时间为40 min对油田废水中油污的去除率分别为79.4%、92.7%;悬浮物的去除率分别为83.5%、94.3%。结果表明TiO 2/MoS 2对油田废水处理效果明显高于纯TiO 2。

水热法制备TiO_2薄膜光催化降解性能的研究

以 Ti( SO4) 2 水溶液为前驱物 ,尿素为沉淀剂 ,采用水热法制备了锐钛矿型 Ti O2 薄膜 ,研究了该薄膜光降解苯甲酸的性能以及 Ti O2

一维TiO_2纳米材料的制备及其光催化性能研究

采用水热法,通过改变水热温度成功制备出一系列一维TiO_2纳米管、纳米线和纳米带。运用X射线衍射、透射电子显微镜、N2吸附-脱附和紫外-可见光谱等手段表征了材料的结构和性质,并考察了一维TiO_2样品光催化降解气相苯的活性。结果表明,一维TiO_2纳米材料具有较高的比表面积,光吸收出现明显的"蓝移",光催化活性较P25有所提高,其中140℃水热温度下制备出的TiO_2纳米管的光催化活性最佳,80min内对气相苯的去除率为77%,终产物CO_2的浓度为625mg/m3。

溶剂热法制备板钛矿型TiO_2

采用溶剂热法,以钛酸四丁酯为钛源、草酸为络合剂,在弱碱性条件下制备了单一相板钛矿TiO_2。通过X射线衍射(XRD)、拉曼光谱、扫描电镜(SEM)、透射电镜(TEM)等测试手段对其进行了结构和形貌分析,考察了溶剂热温度和时间对产物结构、形貌及光催化活性的影响。研究结果表明,溶剂热法所得单一相板钛矿Ti O2为球形颗粒。溶剂热温度和时间对板钛矿结构的形成有重要影响,固定溶剂热时间为8 h时,板钛矿TiO_2的最低成相温度140℃;固定溶剂热温度为180℃时,合成板钛矿TiO_2所需的最短时间为2 h。光催化活性测试结果表明,在紫外光辐照60 min后,所得产物对10 mg·L^(-1)亚甲基蓝溶液的最高脱色率接近于96%。

纳米Ni/TiO_2介孔复合体的组装及结构表征研究

采用溶胶 凝胶工艺制备纳米Ni TiO2 介孔组装复合体。用BET、DSC TGA、XRD及TEM等手段研究其比表面积、晶粒大小、结构及相变特性。结果表明 :在反应溶剂中加入DCCA(干燥控制剂 )和提高n(EtOH) n(Ti)值 (醇钛比 )可使孔径分布由分散变为集中 ,孔容也有所增大 ,Ni的加入明显抑制了基体TiO2 的A—R(锐钛矿—金红石 )的相变 。

Preparation and photocatalytic performance of Cu-doped TiO_2 nanoparticles

Cu-doped TiO2 nanoparticles with different doping contents from 0 to 2.0% （mole fraction） were synthesized through sol-gel method. X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the crystalline structure, chemical valence states and morphology of TiO2 nanoparticles. UV-Vis absorption spectrum was used to measure the optical absorption property of the samples. The photocatalytic performance of the samples was characterized by degrading 20 mg/L methyl orange under UV-Vis irradiation. The results show that the Cu-doped TiO2 nanoparticles exhibit a significant increase in photocatalytic performance over the pure TiO2 nanoparticles, and the TiO2 nanoparticles doped with 1.0% Cu show the best photocatalytic performance. The improvement in photocatalytic performance is attributed to the enhanced light adsorption in UV-Vis range and the decrease of the recombination rate of photoinduced electron-hole oair of the Cu-doped TiO2 nanoparticles.

Ag/TiO2-SiO2的制备及其光催化降解有机污染物的研究

结合溶胶凝胶法和光还原法制备了Ag/TiO 2-SiO 2光催化材料,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、N 2吸附-脱附曲线、紫外—可见漫反射等测试技术对材料形貌、结构等进行了表征,并测试了其对2×10-5 mol/L亚甲基蓝(MB)溶液及实际废水的光催化降解性能。结果表明,适量的Ag负载可有效提高材料的光催化活性。以Ag负载量为5%(质量分数)的Ag/TiO 2-SiO 2(记为TS-A5)为例,TS-A5与商用光催化剂P25相比具有更优越的可见光催化活性;在500 W氙灯做为光源条件下,5次重复使用后TS-A5对MB仍能保持较高的光催化活性,应用于实际废水中可使其COD明显下降,表明该材料具有较好的实际应用潜力。

氮掺杂板钛矿TiO2的制备及光催化性能研究

本文采用水合肼辅助水热法原位制备了具有较好可见光响应能力的氮掺杂板钛矿TiO 2光催化剂。通过X射线衍射(XRD)、拉曼光谱(Raman)、透射电镜(TEM)、X射线光电子能谱(XPS)、紫外可见漫反射光谱(DRS)等测试手段对产物进行了结构、形貌和表面性质分析。以亚甲基蓝(MB)染料溶液为污染物模型,对氮掺杂板钛矿TiO 2的光催化活性进行测试。研究了水合肼用量对产物晶体结构形成及光催化性能的影响。实验结果表明,水合肼的引入导致产物的晶型结构发生变化,随着水合肼用量的增加,产物由单一相板钛矿TiO 2转变为含有板钛矿、锐钛矿甚至金红石的混晶。X射线光电子能谱分析表明,产物中含有少量氮(N)元素,但没有形成含氮化合物。紫外可见漫反射光谱证实所得产物的光谱响应范围稍有拓宽。光催化测试结果表明,适量添加水合肼所得产物的光催化降解性能明显增强,其中,水合肼用量为2.0 mL时所得产物的光催化活性最高,其在可见光辐照120 min后对10 mg·L^-1亚甲基蓝溶液的降解率为81.1%。

掺杂稀土元素La对TiO2纳米粉末光催化制氢性能的影响

为了改善TiO2体系的光催化制氢性能,以La元素为掺杂剂,采用溶胶-凝胶法制备了掺杂La的TiO2纳米粉末,并研究了掺杂La对光催化制氢性能的影响。结果表明:La离子的掺入导致TiO2体系吸收边红移,禁带宽度减小;随着La离子的掺入,样品的制氢性能呈现先增大后减小的趋势。当La离子掺杂的摩尔分数为3%时,体系具有最优光催化制氢性能,光催化3h的制氢量达到577.5μmol/g,比未掺杂的TiO2纳米粉末性能增强了4.1倍,且经5次循环利用后仍表现出良好的光催化稳定性。研究同时发现,La离子具有调节TiO2体系表面氧空位浓度的作用。氧空位有利于光生电子的俘获,实现光生载流子分离,从而有利于增强TiO2体系的光催化制氢性能。

Preparation and properties of a nano TiO_2/Fe_3O_4 composite superparamagnetic photocatalyst

Nano TiO2/Fe3O4 composite particles with different molar ratios of TiO2 to Fe3O4 were prepared via sol-gel method. X-ray diffraction, transmission electron microscopy, and vibration sample magnetometry were used to characterize the TiO2/Fe3O4 particles. The photocatalytic activity of the particles was tested by degrading methyl blue solution under UV illumination （254 nm）. The results indicate that with the content of TiO2 increasing, the photocatalytic activity of the composite particles enhances, while the magnetism of the particles decreases. When the molar ratio of TiO2 to Fe3O4 is about 8, both the photocatalytic activity and magnetism of the TiO2/Fe3O4 particles are relatively high, and their photocatalytic activity remains well after repeated use.

Enhanced photocatalytic activity of TiO_2 nanoparticles using WS_2/g-C_3N_4 hybrid as co-catalyst

TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-sheets by in-situ synthesized technique.The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange(MO).The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2,g-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.

Preparation and photocatalytic activity of PANI/TiO_2 composite film

A PANI/TiO2 composite film deposited on the glass surface was successfully prepared using sol-gel dip-coating technique and chemical oxidation method. The film was characterized using XRD, AFM, and UV. The result showed that the TiO2 film consists of both cuboid-shaped and anatase-phased TiO2 nanoparticles. The average grain size of TiO2 in the film was approximately 20 nm. After coating with PANI, the particle was changed into irregular spherical-shaped and the size was increased up to approximately 35 nm in diameter. UV-Vis spectroscopy analysis indicated that the coating of TiO2 with PANI would result in an enhancement of photocatalytic efficiency and an extension of the photoresponse of TiO2. The band gap of the PANI/TiO2 film was 3.18 eV. The photocatalytic property of the film was evaluated by the degradation of rhodamine-B. It was found that 67.1% and 83.2% of rhodamine-B could be degraded under sunlight and UV irradiation within 120 min using the PANI/TiO2 composite t-tim as photocatalyst.