Structure, photocatalytic and antibacterial activity study of Meso porous Ni and S co-doped TiO2 nano material under visible light irradiation

Undoped and Ni–S co-doped mesoporous TiO2 nano materials were synthesized by using sol–gel method.The characteristic features of as prepared catalyst samples were investigated using various advanced spectroscopic and analytical techniques.The characterization results of the samples revealed that all the samples exhibited anatase phase(XRD),decreasing band gap(2.68 eV)(UV–Vis-DRS),small particle size(9.2 nm)(TEM),high surface area(142.156 m^2·g^-1)(BET),particles with spherical shape and smooth morphology(SEM);there is a frequency shift observed for co-doped sample(FT-IR)and the elemental composition electronic states and position of the doped elements(Ni and S)in the TiO2 lattice analyzed by XPS and EDX.These results supported the photocatalytic degradation of Bismarck Brown Red(BBR)achieved with in 110 min and also exhibited the antibacterial activity on Staphylococcus aureus(MTCC-3160),Pseudomonas fluorescence(MTCC-1688)under visible light irradiation.

Rare Earth Ion Yb^3+ Doping of Bi2WO6 with Excellent Visible-light Photocatalytic Activity

The rare earth ion Yb^3+ doped Bi2WO6 photocatalysts were synthesized by hydrothermal method.Moreover,XRD,XPS,FESEM,TEM,Ramam,N2 adsorption-desorption isotherm measurements and UV-vis diffusion reflectance spectra were used to characterize the Yb^3+ doped Bi2WO6 photocatalysts.The morphology,specific surface area,and pore volume distribution were greatly affected after Yb3+ ions doping.Photocatalytic performance of Bi2WO6 was effectively enhanced after Yb3+ ions doping,6% Yb^3+ doped Bi2WO6 had the best photocatalytic performance,and 96.2% Rhodamine B was degradated after irradiated 30 min,which was 1.29 times that of the pristine one.The enhanced photocatalytic performance was due to the increased specific surface area,decreased energy band gap and inhibition of photoelectron-hole recombination after Yb3+ ions doping.

Degradation of Pollutant and Antibacterial Activity of Waterborne Polyurethane/Doped TiO_2 Nanoparticle Hybrid Films

The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped Ti O2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped Ti O2 were signifi cantly enhanced compared with pure Ti O2 powders. After the hybrid fi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts with kMB of 0.046. In the antibacterial testing, the hybrid fi lms can inhibit E. coli growth. A signifi cant decrease in membrane fl uidity and increase of permeability of E. coli were observed.

Construction of Hierarchical Nanostructured N-doped TiO2 Immobilized Activated Carbon Fiber Porous Composites for Toluene Removal

The hierarchical nanostructured N-doped TiO2 immobilized activated carbon fiber(N-TiO2/ACF)porous composites are fabricated to removal dynamic toluene gas.The results show that nitrogen ions doping and ACF modification can decrease the band gap of TiO2,leading to red shift toward visible light region.Interestingly,N-TiO2/ACF exhibits strongly synergistic effect owing to high surface area,good crystallinity,enhanced bandgap structure and light harvesting.The toluene removal rate of N-TiO2/ACF composites is 2.29 times higher than that of TiO2.The N-TiO2/ACF for toluene degradation followed the Langmuir-Hinshelwood kinetic model,and the rate constant is enhanced 8 times compared with TiO2.The possible photodegradation pathway and mechanisms are proposed.

Photocatalytic Degradation of Isoproturon Pesticide on C, N and S Doped TiO2

TiO2 doped with C, N and S (TCNS photocatalyst) was prepared by hydrolysis process using titanium iso-propoxide and thiourea. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photo electron spectroscopy (XPS), BET surface area, FTIR and diffuse reflectance spectra (DRS). The results showed that the prepared catalysts are anatase type and nanosized par-ticles. The catalysts exhibited stronger absorption in the visible light region with a red shift in the adsorption edge. The photocatalytic activity of TCNS photocatalysts was evaluated by the photocatalytic degradation of isoproturon pesticide in aqueous solution. In the present study the maximum activity was achieved for TCNS5 catalyst at neutral pH with 1 g L-1 catalyst amount and at 1.14 x 10-4 M concentration of the pesticide solution. The TCNS photocatalysts showed higher phtocatalytic activity under solar light irradiation. This is attributed to the synergetic effects of red shift in the absorption edge, higher surface area and the inhibition of charge carrier recombination process.

Ti-MOF Derived N-Doped TiO2 Nanostructure as Visible-light-driven Photocatalyst

Nanostructured N-doped TiO2 photocatalyst has been prepared via a new approach from Ti-based MOF[NH2-MIL-125(Ti)]precursor.The success of N doping enhances light absorption and narrows the bandgap.Moreover,the as-prepared nanostructure is constructed with tiny nanoparticles and resembles a pie-like morphology inherited from the MOF,which accelerates electron transfer.Hence,as a photocatalyst for the degradation of methylene blue(MB)under visible light irradiation,the N-doped TiO2(N-TiO2)nanostructure shows higher photocatalytic activity with a reaction rate constant of 0.018min^-1 than that of the TiO2-P25 and TiO2 under the visible light.

Antibacterial Activity of TiO₂/Ti Composite Photocatalyst Films Treated by Ultrasonic Cleaning

In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.

Synthesis of iron(Ⅲ)-doped nanostructure TiO_2/SiO_2 and their photocatalytic activity

Iron（Ⅲ）-doped nanostructure TiO2-coated SiO2 （TiO2/SiO2） particles were prepared using the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized employing the sol-gel method with TiChas a precursor. The samples were characterized by Fourier transform infrared spectroscopy （FTIR）, SEM, EDS, XPS, and XRD. The experimental results show that TiO2 nanopowders on the surface of SiO2 particles are well distributed, the amount of TiO2 is increased with the adding of coating layers, the pure anatase-TiO2 coating layers are synthesized at 500℃, and the photocatalytic activity of Fe^3＋-doped TiO2/SiO2 is higher than that of undoped TiO2/SiO2.

Structure and visible photocatalytic activity of nitrogen-doped meso-porous TiO_2 layer on Ti6Al4V substrate by plasma-based ion implantation

The nitrogen-doped porous TiO2 layer on Ti6Al4V substrate was fabricated by plasma-based ion implantation of He, O and N. In order to increase the photodegradation efficiency of TiO2 layer, two methods were used in the process by forming mesopores to increase the specific surface area and by nitrogen doping to increase visible light absorption. Importantly, TiO2 formation, porosity architectures and nitrogen doping can be performed by implantation of He, O and N in one step. After implantation, annealing at 650 ℃ leads to a mixing phase of anatase with a little rutile in the implanted layer. By removing the near surface compact layer using argon ion sputtering, the meso-porous structure was exposed on surfaces. Nitrogen doping enlarges the photo-response region of visible light. Moreover, the nitrogen dose of 8×1015 ion/cm2 induces a stronger visible light absorption. The photodegradation of rhodamine B solution with visible light sources indicates that the mesopores on surfaces and nitrogen doping contribute to an apparent increase of photocatalysis efficiency.

Preparation of Nano-TiO_2 Doped with Cerium and Its Photocatalytic Activity

Cerium-doped titanium dioxide nano-powders were prepared through the sol-gel method and the compound sampies were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and UV/Vis diffuse reflectance spectra （DRS）. The photocatalytic activity was evaluated by photocatalytic degradation of phenol in water. The results of XRD, TEM, and DRS show that pure TiO2 and Ce-doped TiO2 powder crystallines are a mixture of anatase and rutile ; the doping can retard the development of the grain size of TiO2 and decrease the diameter of TiO2 from more than 20 nm of pure TiO2 to about 10 nm; the doped TiO2 can improve the light absorption of TiO2 and suitable doping content tends to move the DRS spectrum of TiO2 towards visible light, but too much doping is not good for the light absorption ability. The results of the photocatalytic experiments show that doping with Ce content of 0.08% -0.4% can increase the photocatalytic activity of TiO2; however, doping with Ce content of 0.5% -2.5% can significantly decrease the photocatalytic activity of TiO2. The favorite doping content is 0.4% in the range of our experiments.

PBST/TiO_(2)/MgO复合薄膜的制备及性能

采用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对TiO_(2)/MgO NPs改性,采用溶液共混法制备了聚丁二酸-共-对苯二甲酸丁二醇酯(PBST)/TiO_(2)/MgO NPs纳米复合薄膜,并探讨了其在食品包装方面的应用。研究了改性TiO_(2)/MgO NPs对PBST基体机械、阻隔、抗菌和保鲜性能的影响。结果表明:复合膜的抗拉强度和水蒸汽透过率分别为29.39MPa和2.43×10^(-11) g·m/(m^(2)·s·Pa),相较PBST基体抗拉强度提高了24.32%,水蒸汽透过率降低了32.37%,且对金黄色葡萄球菌(S.aures)和大肠杆菌(E.coli)抑菌效果显著,分别达到98.7%和97.2%,并对圣女果有良好的保鲜性能,当改性后的TiO_(2)/MgO NPs质量含量为5%时,复合薄膜的性能最佳。

Bactericidal and Photoeatalytie Activity of Fe^(3+)-TiO_2 Thin Films Prepared by the Sol-gel Method

Pure TiO2 thin films and iron doped TiO2 thin films on glass substrate were prepared by sol-gel method, and characterized by X-ray diffractometer （XRD）, thermo-gravimetric analysis （TG-DSC）, high resolution transmission electron microscope （HRTEM）, scanning electron microscope （SEM） and UV-Vis spectroscopy, respectively. The experimental results show that the pure TiO2 thin films and iron doped TiO2 thin films can destroy most of the escherichia coli and bacillus subtillis under the irradiation of 365 nm UV-light. However, the iron doped TiO2 thin film is a better photocatalyst than pure TiO2 thin film. The ultrastructural studies provide direct evidences for understanding the bactericidal mechanism of the TiO2 photocatalyst.

Ultrafast one-step synthesis of N and Ti^3＋ codoped TiO2 nanosheets via energetic material deflagration

An energetic-material （NAN3） deflagration method for preparing N- and Ti3＋-codoped TiO2 nanosheets （NT-TiO2） was developed. In this method, N radicals filled the crystal lattice, and Na clusters captured partial O from TiO2. The deflagration process was fast and facile and can be completed within 〈 I s after ignition. The obtained NT-TiO2 exhibited rough surfaces with nanopits and nanoholes. The doping concentration can be regulated by controlling the NaN3 addition. The NT-TiO2 samples showed significant enhancements in the visible-light absorption and photoelectric response. The simultaneously produced N radicals and Na clusters from NaN3 deflagration served as N sources and reduction agents, respectively. Additionally, the high deflagration temperature/ pressure improved the reactivity of N radicals and Na dusters. Thus, the present NaN3 deflagration method was demonstrated as an ultrafast and effective approach to fabricate NT-TiO2 with a visible-light response. The proposed NaN3 deflagration method allows the ultrafast synthesis of new functional materials via the efficient deflagration of energetic materials.

Ce and Er Co-doped TiO2 for rapid bacteria- killing using visible light

Bacterial infection and related diseases are threatening the health of human beings.Photocatalytic disinfection as a simple and low-cost disinfection strategy is attracting more and more attention.In this work,TiO2 nanoparticles(NPs)were modified by co-doping of Ce and Er using the sol-gel method,which endowed TiO2 NPs with enhanced visible light photocatalytic performance but not pure ultraviolet photocatalytic properties compared the untreated TiO2.Our results disclosed that as the doping content of Er increased,the photocatalytic activity of modified TiO2 NPs initially increased and subsequently decreased.The same trend occurred for Ce doping.When the doping dose of Er and Ce is 0.5 mol%and 0.2 mol%,the 0.5Ce0.2Ti-O calcined at 800℃ presented the best antibacterial properties,with the antibacterial efficiency of 91.23%and 92.8%for Staphylococcus aureus and Escherichia coli,respectively.The existence of Er ions is thought to successfully turn the near-infrared radiation into visible region,which is easier to be absorbed by TiO2 NPs.Meanwhile,the addition of Ce ions can effectively extend spectral response range and inhibit the recombination of electrons and holes,enhancing the photocatalytic disinfection activity of co-doped TiO2.

纳米Ag@TiO_(2)、Fe@TiO_(2)和Zn@TiO_(2)的抑菌活性比较

探索常见金属离子掺杂对抑菌片的抑菌性能的影响,为新型纳米TiO_(2)抑菌片的制备与改善提供依据。选择固定质量分数的Ag+、Zn2+和Fe3+掺杂TiO_(2),通过抑菌圈、最小抑菌质量浓度(MIC)与最小杀菌质量浓度(MBC)综合评价其抑菌性能,对微观结构进行表征分析,探讨抑菌性能差异的原因。结果表明:抑菌性能大小顺序为Ag@TiO_(2)>Zn@TiO_(2)>Fe@TiO_(2),Zn@TiO_(2)的抑菌活性较好但抑菌稳定性差。Ag@TiO_(2)对大肠杆菌和金黄色葡萄球菌的MIC、MBC均是10、20 mg/L,Zn@TiO_(2)对大肠杆菌和金黄色葡萄球菌的MIC、MBC均是30、50 mg/L。表征发现抑菌活性强弱主要归因于纳米TiO_(2)表面与金属离子共同产生的活性位点数量及稳定性,与孔结构或表面官能团的关联不大。

Mo掺杂TiO_2/AC负载膜的制备及光催化活性

以钼酸铵和钛酸丁酯为原料 ,用溶胶 凝胶法在活性炭 (AC)表面制备了Mo掺杂TiO2 /AC负载膜。用紫外可见吸收光谱、透射电镜和X射线衍射法对负载膜进行了表征。考察了Mo掺杂TiO2 /AC负载膜对甲基橙和氧化乐果水溶液的光催化降解活性。结果表明 ,Mo掺杂TiO2 /AC负载膜的TiO2 为锐钛矿和金红石的混合晶相 ,而未掺杂的TiO2 /AC负载膜其TiO2 为金红石晶相。Mo掺杂使TiO2 /AC负载膜的吸收带边位置发生红移。Mo质量分数为 1 5 %时 (以TiO2 质量计 ) ,负载膜的光催化活性最高。

TiO_2/Ag型抗菌活性碳纤维的制备和性能表征

采用涂覆和焙烧的简便方法 ,将载银二氧化钛 (TiO2 Ag)均匀地沉积在活性碳纤维表面。利用扫描电镜、氮气吸脱附等对活性碳纤维结构进行表征 ,研究发现活性碳纤维的微孔结构、活性碳纤维的高吸附性能基本保持不变。利用改良抑菌圈法研究了这类TiO2 Ag活性碳纤维对大肠杆菌、金黄色葡萄球菌、枯草杆菌和链球菌的杀灭效果。结果表明 ,因Ag和TiO2 相互协同作用 ,TiO2 Ag活性碳纤维的抗菌性大大提高 ,当Ag含量为 0 .5 %时 ,在 37°C培养 4小时后 ,TiO2 Ag活性碳纤维对大肠杆菌、金黄色葡萄球菌就有很强的抗菌能力。由于TiO2 特殊的光催化特性 ,使TiO2 Ag活性碳纤维不仅适用于水的净化抗菌处理 ,更适用于空气的净化抗菌处理。

不同掺铁方式对TiO_2薄膜光催化活性的影响

采用溶胶凝胶工艺在普通玻璃表面制备出表面掺铁与体相掺铁的TiO2 薄膜。运用SEM ,XRD和AES等技术研究了复合薄膜的表面特征。以光催化降解甲基橙溶液为模型反应 ,表征薄膜的光催化活性。结果表明 :体相掺铁时 ,薄膜的最佳n(Fe) /n(Ti)为 0 .12 %;表面掺铁时 ,薄膜的最佳n(Fe) /n(Ti)为 1.5 %。表面掺铁薄膜的最佳光催化表观速率常数比体相掺铁的最佳值要高 1.5倍。并从载流子分离效率等方面进行了机理探讨。

掺银TiO_2复合薄膜的制备和光催化性能的研究

研究了通过 sol- gel工艺在普通玻璃表面制备均匀透明的掺银锐钛矿型 Ti O2 光催化复合薄膜。研究表明 :Ti O2 复合薄膜由 Ti O2 球形颗粒组成 ,其颗粒大小在 5 0 nm～ 10 0 nm;薄膜的厚度每镀一次增加约 0 .0 9μm;薄膜中出现的锐钛矿在 (10 1)面具有一定的择优取向。甲基橙水溶液的光催化降解实验表明 :掺银 Ti O2 复合薄膜的表观降解速率常数明显高于未掺银 Ti O2 薄膜的表观降解速率常数 ,这为进一步提高 Ti O2 薄膜的光催化活性开辟了新的途径。

M_o(V)掺杂纳米TiO_2的光化学活性封闭及表征

为了封闭TiO2 的光化学活性 ,降低TiO2 光敏性 ,提高它在使用介质中的耐候性 ,本实验分别用两种方法制备了钼掺杂的纳米TiO2 样品 ,并用XRD和TEM对样品进行表征 ,所得样品均为锐钛矿型 ,颗粒尺寸在 5 0nm以下。通过紫外屏蔽性能测试和光化学活性测定实验 ,结果表明 ,共沉淀法掺杂和负载法掺杂均能降低纳米TiO2 的光化学活性 ,并且共沉淀法所制样品的紫外屏蔽能力优于负载法所制样品的紫外屏蔽能力 ,这对纳米TiO2 能较好地应用于化妆品、涂料工业具有重要意义。