TiO2薄膜光催化剂的性能研究

采用溶胶-凝胶法在玻璃管上制备了透明的TiO₂薄膜，并利用XRD、Raman、UV-Vis和XPS技术对薄膜进行了表征。结果表明,在773 K焙烧的TiO₂样品在290～330 nm处的吸收明显强于573 K焙烧的样品。在573 K焙烧的情况下，薄膜基本为非晶态，但却表现出良好的光催化活性，并随着负载层数的增加，薄膜的光催化活性逐渐增加。在573 K以上，随焙烧温度的升高，TiO₂薄膜的光催化活性逐渐降低。     

TiO2、ZnO和TiO2/ZnO三种氧化物粉体材料的抗菌性能对比

氧化物具有化学性质稳定、原材料丰富易得的优点,其作为抗菌材料日益受到关注。对氧化物的抗菌性能及影响因素开展深入研究,能够为新型抗菌材料的开发提供科学依据。通过溶胶-凝胶法制备出了TiO₂/ZnO复合粉体,并将其与TiO₂、ZnO进行对比,分别对它们的晶相结构、微观形貌和粒径进行了表征。利用大肠杆菌ATCC25922作为受试菌株,通过抑菌环试验和菌液接触试验对3种氧化物粉体材料的抗菌性能进行测试。考察了钛锌比、光照等条件对抗菌效果的影响。结果表明,所使用的TiO₂主要由锐钛矿相和金红石相组成,ZnO主要为六方纤锌矿相,制备出的TiO₂/ZnO则主要是锐钛矿型TiO₂在六方纤锌矿型ZnO的孔隙间沉积而成,这3种粉体材料的粒径由大到小分别为TiO₂/ZnO、TiO₂和ZnO。从抑菌环和菌液接触试验的结果可以看出,ZnO粉体材料的抗菌效果明显优于TiO₂粉体材料,ZnO和TiO₂/ZnO在黑暗条件下仍有良好的抗菌性能,但在可见光照射条件下抗菌效果更佳。ZnO含量是TiO₂/ZnO复合材料抗菌性能的关键因素。制备TiO₂/ZnO粉体材料时的煅烧温度对其抗菌性能没有明显影响。     

An experimental and theoretical study on the photocatalytic antibacterial activity of boron-doped TiO2 nanoparticles

Boron-doped titanium dioxide nanoparticles (B–TiO₂ NPs) were prepared by a sol-gel method. The physicochemical properties of B–TiO₂ NPs were characterized by X-ray diffraction, transmission electron microscopy, ultraviolet–visible diffuse reflectance spectroscopy and photoluminescence spectroscopy. The band structure and electrical properties of B–TiO₂ NPs were investigated using the first-principle. The effects of the concentration gradient of doping B ions on the photocatalytic antibacterial activity of B–TiO₂ NPs under visible-light irradiation were investigated by the inhibition zone method and the shaking flask method. The experimental results show that B–TiO₂ NPs are mainly composed of the anatase phase, but no B-related phase was observed. With the increase of the doping amount of boron ions, the particle size decreases and the specific surface area increases. B atoms mainly exist in the form of substitutional dopant and interstitial dopant. Theoretical calculations reveal that B atoms in the TiO₂ matrix exist much more easily as interstitial dopant, but B–TiO₂ NPs composed of B substituted dopant have better photocatalytic performance. The results of the antibacterial assays show that B–TiO₂ NPs have strong antibacterial activities and some bactericidal activities. Finally, the mechanism of the antibacterial activity of B–TiO₂ NPs are examined.     

Effect of TiO2 nanoparticles on the horizontal hardness properties of Sn-3.0Ag-0.5Cu-1.0TiO2 composite solder

The improvement in the hardness of Sn-3.0Ag-0.5Cu solder alloy reinforced with 1.0 wt % TiO₂ nanoparticles was evaluated by nanoindentation. A specific indentation array was performed on four different horizontal cross sections of the composite solder with different heights and diameters, in order to verify the mixing homogeneity of TiO₂ nanoparticles within the Sn-3.0Ag-0.5Cu solder paste during the ball milling process. The phase analysis indicated successful blending of the Sn-3.0Ag-0.5Cu with the TiO₂ nanoparticles. According the scanning electron microscopy micrographs, presence of the TiO₂ nanoparticles reduced the size of the Cu₆Sn₅ and Ag₃Sn intermetallic compound phases. Incorporation of the 1.0 wt % TiO₂ nanoparticles improved the hardness values up to 26.2% than that of pure SAC305. The hardness values increased gradually from the top cross sections towards adjacent to the solder/substrate interface. The mechanism of the hardness improvement attained by the TiO₂ nanoparticles addition were also investigated on the horizontal cross sections of the samples.     

TiO2光催化膜的制备及其性能研究

采用溶胶-凝胶法制备了Ti O₂粉体,并以聚乙烯醇和聚多巴胺为载体,采用浇铸法制备出Ti O₂光催化薄膜。对膜的耐水性和光催化降解性能进行了测试。结果表明,光照30min甲基橙的降解率为89.33%,光照60min甲基橙的降解率为93%。随着薄膜内Ti O₂添加量的增加,膜的光催化性能逐渐增强,在水中的吸水率逐渐降低。     

Defect-mediated optical properties of Fe-substituted TiO2 nanoparticles

Here, sol–gel derived Fe–TiO₂ anatase nanoparticles with varying concentrations of Ti_(1–x)Fe_xO₂ (x = 0%, 1%, 5%, 10%) were prepared. The structural, morphological, and optical properties of prepared samples were studied. X-ray diffraction (XRD) patterns show the formation of pure anatase phase. The mean crystallite size of Fe–TiO₂ decreases with increase in the concentration of Fe. Fourier transform infrared spectroscopy (FTIR) spectra confirmed the presence of Ti–O vibrational band for all the samples. In Raman spectrum, peak broadening and red shifting linked with Eg ∼144 cm^–1 divulge the Fe substitution at Ti sites into host lattice structure. Photoluminescence (PL) spectra verified nine peaks related to near band-edge emission and various defect states. The UV–vis diffuse reflectance spectra represent redshift and reduction in the bandgap energy. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations show that the size of the grains decreases with increase in Fe doping concentration. The study shows that Fe-doped TiO₂ anatase phase nanoparticles are suitable for photocatalytic activity and solar cell applications.     

水热合成二氧化钛纳米颗粒及光致发光性能研究

以价格较为低廉的钛酸丁酯为钛源,不同添加量的十六烷基三甲基溴化铵（CTAB）为模板剂,采用水热合成法制备二氧化钛纳米颗粒。利用氮吸附仪、扫描电子显微镜（SEM）、X射线衍射仪（XRD）、荧光光谱仪（PL）对材料进行结构分析及光致发光性能测试。结果表明,所制备的二氧化钛纳米材料均为锐钛矿结构,粒径较小的纳米颗粒堆积形成介孔结构。样品具有特殊的光致发光特性,由于纳米颗粒粒径大小不同,孔径大小不等使得光致发光特性的强度产生较大差异,发射峰位置产生明显红移。     

铝包膜TiO2的膜层结构对颜料性能的影响

以偏铝酸钠为包膜剂，采用液相沉淀法在TiO2粒子表面包覆Al2O3膜。采用TEM、SEM、XRF等手段表征无机膜层，通过测试包膜TiO2样品的耐候性、光泽度、亮度等评价其颜料性能。研究以HRTEM结合晶格计算分析膜层氧化铝晶型，并对包膜pH和温度对包膜TiO2的膜层结构和颜料性能的影响进行了实验研究。结果表明，酸性条件下包膜TiO2的膜层氧化铝为无定形，样品耐候性较优；pH=10时膜层氧化铝为勃姆石型和拜耳石型混合晶型，以勃姆石型为主，产品颜料性能优异；pH>11时膜层氧化铝为拜耳石型，产品颜料性能较差。温度升高会增加膜层氧化铝的结晶度，提高包膜TiO2产品的颜料性能。     

The effect of TiO2 nanoparticles on the properties of sulfonated block copolymers

Block copolymers composed of styrene and different elastomeric blocks were sulfonated to high ion exchange capacities (IECs). Titanium dioxide (TiO₂) nanoparticles were added to these polymers to improve their mechanical and thermal stabilities, while influencing their transport properties for direct methanol fuel cell (DMFC) applications. Materials properties as proton exchange membranes (PEMs) were analyzed using: FT‐IR, water absorption, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), IEC, methanol permeability, and proton conductivity studies. Although there was no effect of TiO₂ nanoparticles on the thermal stability of the membranes, significant changes were observed in the mechanical properties of both sulfonated block copolymers studied. Water absorption increased at low TiO₂ content, but was then reduced with the incorporation of more nanoparticles. To enhance the interaction between the inorganic fillers and the polymers, sulfonic and amino groups were attached to the surface of the titania nanoparticles. The effect of sulfonated nanoparticles on the properties of the materials was more significant than the effect of the amino functionalized nanoparticles on all the properties evaluated, suggesting enhanced chemical interactions with the ionic domains of the polymer membranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42651.     

AgO/TiO_2纤维复合材料的制备及其杀菌性能

采用液相沉淀法将纳米氧化高银与二氧化钛进行复合。水热法处理得到二氧化钛纤维后,加入到制备氧化高银的反应液中,即液相沉淀法制取样品。通过X射线衍射(XRD)、透射电子显微镜(TEM)、能谱(EDS)对纳米氧化高银颗粒的结构、形貌和元素含量分析进行表征。采用抑菌圈法,用制备的AgO/TiO2对枯草芽孢杆菌进行抗菌性能测试。结果表明,氧化高银与二氧化钛纤维的质量比为2:1时,杀菌效果最好。     

Effect of the sonication and coating time on the photocatalytic degradation of TiO2, TiO2-Ag,and TiO2-ZnO thin film photocatalysts

Abstract

Today, the ultrasound utilizing for material synthesis has been extensively investigated. The unusual acoustic cavitation phenomenon caused by ultrasonic waves has created a new world for the production of high efficiency photocatalysts with new structures. In this study, TiO₂, TiO₂-Ag, and TiO₂-ZnO thin film photocatalysts were prepared using titanium isopropoxide Ti[OCH(CH₃)₂]₄, zinc acetate dehydrates (CH₃COO)₂Zn·2H₂O, and silver nitrate AgNO₃ by a sol–gel method under the ultrasonic irradiation. The prepared photocatalysts were characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive spectroscopy. The SEM images showed that the Ag and ZnO particles were evenly dispersed in the photocatalysts due to the ultrasonic irradiation, and Ag particles were approximately 90?nm, which is relatively small compared to the photocatalysts which is not treated with ultrasonic irradiation. The catalytic activity of the photocatalysts was determined using Acid Red 27 dye. The most excellent catalytic degradation was obtained with TiO₂-ZnO thin film photocatalyst. In comparison to the conventional photocatalyst, the efficiency of photocatalytic activity of the photocatalyst produced under ultrasonication has been increased due to the reduced size of Ag and ZnO and its uniform dispersion.     

Effects of TiO2 and GO nanoparticles on the thermomechanical properties of bioactive poly-HEMA nanocomposites

Iranian Polymer Journal - Bioactive polymeric nanocomposites are indispensable materials and have received great attention owing to their diverse applications in human body. In this study, a...     

TiO2/SiO2复合薄膜的制备及其自清洁性能

利用热陈化法得到的纳米TiO2粒子及SiO2聚合物胶粒通过浸渍-提拉技术制备了具有自清洁功能的TiO2/SiO2复合薄膜。考察了SiO2的复合比例对薄膜的表面形貌、透光率、光致亲水及自清洁性能的影响。随着SiO2复合体积分数的增大,薄膜的表面粗糙度、可见光透过率、光致亲水及自清洁性能显示了相似的变化规律。即在V(SiO2)=25%左右时,薄膜的各项特性或性能达到最大值或最小值。该薄膜在室外放置28天后,仍能显示超亲水性能。     

Al nanoparticles decorated Er:TiO2 thin film based plasmonic photodetector

Aluminum (Al) nanoparticles (NPs) patterned Erbium-doped Titanium dioxide (Er:TiO₂) thin films (TFs) were synthesized by the combination of sol-gel and glancing angle deposition (GLAD) technique inside the thermal evaporation system. Effects of Al NPs on electrical and optical properties of the Er:TiO₂ TF were experimented and systematically analyzed. Size of NPs was estimated from the field emission scanning electron microscopy (FESEM) image. Diameter of the maximum number of Al NPs was determined to be ～13 nm. The presence of Al was confirmed from the energy dispersive X-ray (EDX) spectra. The optical absorption at around 315 nm revealed the plasmonic resonance of Al NPs. The Au/Er:TiO₂/Al NPs/Er:TiO₂/p-Si Schottky contact-based plasmonic photodetector (PD) was fabricated, which showed excellent photosensitivity under both forward and reverse bias conditions. The responsivity was calculated at an applied voltage of 1 V, which exhibited a high response in the UV region with peak responsivity at 330 nm and 380 nm. The device showed fast switching behaviors under the illumination of 350 nm with a rise time of ～0.55 s and fall time of ～0.13 s. A simple theoretical approach was adopted to evaluate some important parameters of the plasmonic device like photoconductive gain, transit time, and mobility of electrons. Detectivity (1.13 × 10¹² Jones) and noise equivalent power (NEP) (2.46 × 10^?14 W) at 330 nm indicate the suitability of the device as a sensitive UV PD. Hence, the embedded plasmonic Al NPs on Er:TiO₂ TF-based devices can commercially emerge as an efficient and cost-effective UV photodetector.     

TiO2基纳米复合抗菌剂研究

以Ti(SO4)2和AgNO3为主要原料,用沉淀法制备了以TiO2为基质的纳米复合抗菌剂。用振荡烧瓶试验法检测了抗菌剂的抗菌性能,结果表明该抗菌剂质量浓度100mg/L、振荡接触60min,对大肠杆菌、金黄色葡萄球菌和白色念珠菌的抑杀率均可达99%以上。还初步探讨了纳米抗菌剂光催化氧化和接触反应的抗菌机理。     

Effect of the film thickness on the fabrication of ordered TiO2 thin film microstructures by transfer printing

This paper describes a transfer printing technique for directly patterning ordered TiO₂ thin films onto Si substrates. Two- or three-dimensional TiO₂ structures can be fabricated onto an Si substrate depending on the coating film thickness, which is controlled via the liquid phase deposition process parameters and attractive interaction forces between a poly(dimethylsiloxane) stamp and a polyelectrolyte layer during the transfer printing process. This additive transfer process is mediated by the presence of a thiol (SH)-terminated 3-mercaptopropyltrimethoxysilane self-assembled monolayer on the wafer surface. The transferred patterns are chemically bonded to the wafer surface, exhibiting strong adhesion. The attractive interaction forces between the stamp and the polyelectrolyte layer was weak enough to allow ready detachment of the patterns from the stamp during printing. Even the parts of a continuous TiO₂ film that are not in contact with the substrate effectively transfer to form a free-standing structure. With long and short deposition times, three-dimensional structures and ordered two-dimensional round-hole grid structures, respectively, are obtained after the removal of the stamps.     

ZnO/C/TiO2复合纳米材料制备及其光催化性能

以金属有机骨架MOF-5为前驱体,在氮气气氛下高温处理得ZnO/C,通过水热法将ZnO/C负载到TiO2中获得ZnO/C/TiO2纳米复合光催化剂,对其晶体结构、形貌特征、成分等进行了表征,采用正交实验法考察了MOF-5处理温度、ZnO/C负载量、钛酸丁酯加入量对复合光催化剂催化降解甲基橙性能的影响. 结果表明,TiO2的比表面积为87.5 m2/g, ZnO/C/TiO2的比表面积为109.0 m2/g. 制备ZnO/C/TiO2的最佳条件为MOF-5处理温度600℃,ZnO/C负载量0.07 g,钛酸丁酯加入量1.5 mL. 甲基橙用紫外灯照射90 min,以TiO2为催化剂时降解率为62.1%,以ZnO/C/TiO2为催化剂时降解率达99.5%,光催化活性大大提高.     

Effect of TiO2 on the properties of ultralow-cement alumina-spinel castables

An ultralow-cement castable based on the Al₂O₃-MgO spinel system is synthesized by the interaction of fused alumina (70%) and sintered periclase (30%) using a calcium aluminate cement (75% Al₂O₃) and a co-deposited gel Al(OH)₃ and Mg(OH)₂ as the castable bond. The addition of TiO₂ and its effect on the apparent density, volume shrinkage, open porosity, and true density of sintered specimens (at 1400–1600 °C) is studied. Results of a microstructure analysis using x-ray diffractometry and scanning electron microscopy are reported. The additive TiO₂ is shown to exert a positive effect on the formation of spinel and physicomechanical properties of the system. __________ Translated from Novye Ogneupory, No. 12, pp. 64–68, December, 2005.     

Effect of Si doping on the photocatalytic activity and photoelectrochemical property of TiO2 nanoparticles

Si-doped TiO₂ nanoparticles with anatase crystalline phase were prepared by a hydrothermal method using acetic acid as the solvent. Photoelectrochemical studies showed that the photocurrent value for the 15% Si-doped TiO₂ electrode (54.4 μA) was much higher than that of the pure TiO₂ electrode (16.7 μA). In addition, the 15% Si-doped TiO₂ nanoparticles displayed the highest photocatalytic activity under ultraviolet light irradiation. So doping suitable amount of Si in TiO₂ nanoparticles was profitable for transferring photogenerated electrons and inhibiting the recombination of photogenerated electrons and holes. As a result, the photocatalytic activity of TiO₂ nanoparticles was improved.     

Influence of TiO2 on the physical properties of low-temperature ceramic vitrified bond and mechanical properties of CBN composites

The microstructures and properties of vitrified bond abrasive tools made of CBN grains and advanced vitrified bond systems with different TiO₂ doping amounts were investigated. Based on the experimental observations and analysis, the incorporation of TiO₂ in appropriate amount (4 wt.%) was beneficial to the improvement on flowing ability and thermal expansion property of the vitrified bond systems, and mechanical properties of the CBN composites including bending strength and Rockwell hardness were obviously improved. On the basis of discussion for microstructure, the CBN grains were better covered by vitrified bond and acquired less pores when the content of TiO₂ reached 4 wt.%. These results were related to the role of TiO₂ in the glass network structure which was analyzed by Fourier transform infrared spectroscopy (FTIR).