基于SnO2/TiO2/Au NPs纳米复合材料发展光电化学方法特异性检测唾液酸

制备了氧化铟锡（ITO）/二氧化锡（SnO₂）/二氧化钛（TiO₂）/金纳米粒子（Au NPs）纳米复合电极（ITO/SnO₂/TiO₂/Au NPs）,并利用它发展了可以选择性检测唾液酸（SA）的光电化学（PEC）法.采用旋涂法制备了ITO/SnO₂电极,并通过静电纺丝和磁控溅射技术在ITO/SnO₂表面原位合成了TiO₂纳米纤维和Au NPs.与单纯SnO₂比,ITO/SnO₂/TiO₂/Au NPs纳米复合电极的光电性能显著提高.这可能与Au NPs的局域表面等离子体共振效应（LSPR）和TiO₂/SnO₂异质结之间的协同作用密切相关.之后,通过金硫键（Au-S）将四巯基苯硼酸（4-MPBA）修饰在ITO/SnO₂/TiO₂/Au NPs电极表面,利用4-MPBA和SA之间的非特异性酯化反应,发展了可以特异性检测SA的PEC传感平台.     

Au@SiO2 core/shell nanoparticle-decorated TiO2 nanorod arrays for enhanced photoelectrochemical water splitting

To improve the separation efficiency of photoinduced charge carries,Au@SiO2nanoparticles(NPs)with core–shell structure were loaded onto the surface of TiO2nanorods grown on fluorine-doped tin oxide substrate by a facile two-step process.The resulted Au@SiO2/TiO2photoanodes were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,as well as photoelectrochemical measurements.Compared with pristine TiO2nanorod film,the Au@SiO2/TiO2films showed remarkable enhancement in photoelectrochemical water splitting,with incident photonto-current conversion efficiency increasing from 31%to37%at 380 nm at 0.7 V versus saturated calomel electrode.This could be interpreted by the effect of metallic surface plasmon resonance of Au@SiO2NPs,which would generate an intense electromagnetic field with spatially nonhomogenous distributed intensity.As a result,the charge carriers generated in the near-surface region of TiO2nanorods could be easily separated.This modification method based on the effect of metallic surface plasmon resonance for promoted charge carrier separation provides a promising way to develop semiconductor photoelectrodes with high solar water-splitting performance.     

水热体系下二氧化钛与氧化石墨烯复合纳米晶的合成

 200 ℃下四方结构的二氧化钛(TiO2)与氧化石墨烯(GO)复合纳米晶在一个装有适量钛酸四丁酯、无水乙醇、氧化石墨烯和蒸馏水的密闭的水热釜中加热12 h后被制备。X射线粉末衍射仪（XRD)、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等一系列分析仪器被运用来揭示二氧化钛与氧化石墨烯复合纳米晶是由粒径大约160 nm的四方结构的二氧化钛纳米晶与氧化石墨烯复合而成,通过紫外吸收对其光学性能进行了必要的测试。
     

Preparation and performance of dye-sensitized solar cells based on ZnO-modified TiO<Subscript>2</Subscript> electrodes

The ZnO-modified TiO₂ electrode was prepared by adding Zn(CH₃COO)₂·2H₂O to the TiO₂ colloid during the sol-gel production process, and was used in dye-sensitized solar cells (DSCs). The open circuit voltage (V _OC) and fill factor (ff) of the cells were improved significantly. The performances of the ZnO-modified TiO₂ electrode such as dark current, transient photocurrent, impedance, absorption spectra, and flat band potential (V _fb) were investigated. It is found that the interface charge recombination impedance increases and V _fb shifts about 200 mV toward the cathodic potential. The effect mechanism of ZnO modification on the performance of DSCs may be that ZnO occupies the surface states of the TiO₂ film.     

Preparation of nano-crystal N-Zn/TiO<Subscript>2</Subscript> anode films and the effects of co-sensitization on the performance of dye-sensitized solar cells

A nano-crystal N-Zn/TiO₂ anode film was prepared using a combined technology. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry characterizations showed that the two elements N and Zn were doped into nano-crystal TiO₂ successfully. This resulted in a strong redshift in the UV-Visible spectrum. UV-Visible measurements showed that the light absorption of N719 and P3OT were complementary and covered the entire visible region. This led to a high utilization of visible light. Solar cells based on the N-Zn/TiO₂ anode film were co-sensitized using P3OT and N719. The cells have a short-circuit current density of 7.91 mA/cm², an open-circuit photovoltage of 0.659 V, and a photoelectric conversion efficiency of 2.64%. Also, the relationship among the N-Zn/TiO₂-film anode’s electric structure, the dye’s LUMO, electrochemical impedance, and photoelectric conversion efficiency are discussed in the paper.     

2种晶型纳米二氧化钛材料对A549细胞的毒性效应

利用LDH活性检测的分子生物学手段结合TEM技术研究金红石型和锐钛矿型纳米TiO2材料对人肺腺癌细胞(A549)的作用及可能的机制.LDH活性检测发现:与对照组相比,金红石型300μg/mL浓度组对细胞膜的损伤最大.TEM显示,在细胞内或周围发现一些纳米TiO2颗粒,但2种晶型纳米TiO2的存在形式有所不同,并且金红石型实验组中,板层体数量明显增多,部分纳米颗粒缠绕于板层体中.这说明,2种晶型纳米TiO2材料对细胞的细胞膜及其它细胞器造成了一定的影响,且纳米TiO2材料的晶体构象不同,引起的毒性效应存在着显著差异.     

TiO2复合对La2/3(Ca0.65Ba0.35)1/3MnO3电输运和磁电阻效应的影响

利用甘氨酸-硝酸盐（GNP）法合成了La_2/3(Ca_0.65Ba_0.35)_1/3MnO₃纳米颗粒体系, 与TiO₂复合后, 得到La_2/3(Ca_0.65Ba_0.35)_1/3MnO_3/xTiO₂体系（x=0,0.02,0.035,0.055,0.09,0.17）, 通过X射线衍射、 Raman光谱、 扫描电子显微镜和磁电阻效应测试, 对合成产物的结构及性能进行表征. 结果表明, 样品均成立方对称结构, 复合使低场磁电阻增强, 电阻率增大.     

Structure and photocatalytic properties of TiO<Subscript>2</Subscript>-Graphene Oxide intercalated composite

TiO2-Graphene Oxide intercalated composite (TiO2-Graphene Oxide) has been successfully prepared at low temperature (80°C) with graphite oxide (GO) and titanium sulfate (Ti(SO4)2) as initial reactants.GO was firstly exfoliated by NaOH and formed single and multi-layered graphite oxide mixture which can be defined as graphene oxide,[TiO]2+ induced by the hydrolysis of Ti(SO4)2 diffused into graphene oxide interlayer by electrostatic attraction.The nucleation and growth of TiO2 crystallites took place at low temperature and TiO2-Graphene Oxide composite was successfully synthesized.Furthermore,the photocatalytic properties of TiO2-Graphene Oxide under the irradiation of UV light were also studied.The results show that the degradation rate of methyl orange is 1.16 mg min-1 g-1(refer to the efficiency of the initial 15 min).Compared with P25 powder,this kind of intercalation composite owns much better efficiency.On the other hand,the reusable properties and stable properties of TiO2-Graphene Oxide intercalated composite are also discussed in this paper.At last,crystalline structure,interface status,thermal properties and microscopic structure of TiO2-Graphene Oxide were characterized by X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),thermogravimetric analysis (TGA),field emission scanning electron microscopy (FESEM) and high-resolution Transmission Electron Microscopy (HRTEM).Also,we have analyzed major influencing factors and mechanism of the composite structures which evidently improve the photocatalytic properties.     

The hemocompatibility and the reabsorption function of TiO2 nanotubes biomembranes

A novel high-intensity TiO2 nanotubes array membrane was fabricated via electrochemical anodization of highly pure titanium foil and an open-ended TiO2 nanotubes array membrane was obtained by HF gas etching at the bottom of the nanotubes. Pig tubular epithelial cells (LLC-PK1) and vascular endothelial cells (ECV304) were cultivated on the open-ended TiO2 nanotubes surface through a mixing implantation method and TiO2 nanotubes biomembrane materials with physiological function were successfully produced. Hemocompatibility of glass slides, pure titanium, TiO2 nanotubes without cells and TiO2 nanotubes with culture cells were investigated by the plasma recalcification time method and reabsorption of sodium and potassium were measured by custom-designed devices. The results show that the hemocompatibility of the TiO2 nanotubes array membrane with culture cells was superior to the control group, and the biomembrane has an excellent reabsorption function. This demonstrates that a TiO2 nanotubes array membrane has excellent physiological function and is an ideal candidate material for biological dialysis.     

Al掺杂TiO_2的制备及酸化处理对其光催化活性的影响

锐钛矿相TiO2的光催化活性高于金红石相。采用化学溶液分解法制备了Al掺杂锐钛矿TiO2,并用硝酸对其进行酸化处理。利用TG-DTA、XRD、FTIR、BET和UV-vis等手段对样品进行了表征,通过对甲基橙的降解分析了酸化处理对Al掺杂TiO2光催化活性的影响。结果表明:掺杂Al能有效抑制TiO2由锐钛矿向金红石转变。酸化处理因能增大Al掺杂TiO2的比表面积而使其光催化活性提高。Al/Ti掺杂比为1∶4的样品在酸化处理后具有的光催化活性最高,60min后对甲基橙的降解达到100%。     

稀土氧化物掺杂对TiO2/沸石光催化性能的影响

以钛酸丁酯和稀土氧化物为原料, 采用溶胶 凝胶法制备了镧、 钕和镱稀土离子掺杂TiO₂/沸石光催化剂. 通过XRD和IR方法对样品进行表征, 研究了不同沸石粒径及不同稀土氧化物掺杂量(质量分数)对农药敌敌畏光催化降解性能的影响. 结果表明, 当沸石最佳粒径为0.15 mm, La³⁺掺杂量质量分数为3.0%时（以TiO₂质量计）, 稀土离子的掺杂可显著提高TiO₂//沸石的光催化降解性能.     

氧化铈纳米材料的合成及其在癌症治疗方面的研究进展

近年来，氧化铈纳米颗粒（CeO₂NPs）材料的合成及其在生物医学，尤其是在癌症治疗方面的应用研究引起了研究者们的广泛关注.一方面，CeO₂NPs对癌细胞具有明显的细胞毒性，能用于光动力治疗（PDT）和化学药物治疗（CHT）等方面，并且能够使癌细胞对放射治疗（RT）敏感；另一方面，CeO₂NPs能保护正常细胞，具有抗氧化活性.这种具有差异细胞毒性的材料为开发新型癌症治疗试剂提供了新的思路.文章系统地介绍了近年来CeO₂NPs的合成及其在癌症治疗方面的研究进展，希望对该材料将来的研究工作起到一定推动作用.     

I-doping of anodized TiO<Subscript>2</Subscript> nanotubes using an electrochemical method

In order to obtain TiO2 with high photocatalytic activity, a cathode reduction was used to dope I⁷⁺ and I⁵⁺ into TiO₂ nanotubes of anodized Ti in C₂H₂O₄•2H₂O + NH₄F electrolyte. SEM images show that the anodization method integrated the preparation with the doping process, which for nonmetals-doping is advantageous to maintain the morphological integrity of TiO₂ nanotubes. I⁷⁺-I⁵⁺-doping enhances the UV response of TiO₂ and result in a red-shift. Under UV/visible irradiation, a I⁷⁺-I⁵⁺-doped sample (400°C) showed the highest I_ph and photocatalytic efficiency. A part of I^– in the I⁷⁺-I⁵⁺-doped sample is involved in the UV response, the red-shift and the higher I_ph.     

Fabrication and character ization of electrospun TiO2/CuS micro–nano-scaled composite fibers

A process to fabricate a kind of novel micro–nano scaled TiO2/CuS composite fibers by electrospinning technique and chemical precipitation method was developed in the present study. The microstructures and photoelectronic properties of the fibers were characterize d using SEM, FT-IR, UV–vis and fluorescence spectroscopy. The results revealed that the TiO2 portion in the composite fibers was a mixture rutile and anatase phases while TiO2 and CuS had been fully composite. The fibers had smooth surface with a diameter of 50–300 nm. Comparing with pure TiO2 fiber, the TiO2/CuS micro–nano-scaled composite fibers exhibited a strong absorption in the visible light region and the efficiency of photo-induced charge separation were enhanced. This composite system is of widely potential applications in the areas such as solar cells, supercapacity, photocatalysis, etc.     

High-pressure polymorph of TiO2-II from the Xiuyan crater of China

Abundant TiO2-II, a high-pressure polymorph of titanium dioxide, was found in the gneiss fragments of impact-produced breccias from the Xiuyan crater. Rutile in the gneiss was severely fragmented and fine-grained clasts less than 2 ~tm in size had been transformed to TiO2-II. Irregular thin layered TiO2-II is also observed in coarse-grained ruffle fragments, where the TiO2-II layers distributes along fractures and cracks in rutile, About 30 percent of rutile in the gneiss had been transformed to TiO2-II. Fine grains of TiO2-II display light bluish grey to light yellow brown in plane-polarized reflected light. Crystallographic investigation shows that TiO2-II has an orthorhombic structure with space group Pbcn. The cell parameters are a=4.543（1）/~, b=5.491（9）/~ and c=4.895（2） ,~. Its empirical formula calculated on the basis of two oxygen atoms can be written as （Tio.985Feo.oosNbo.oor- Si0.003Zr0.0Ol）l.0O302, or simply formula TiO2. According to the shock effects of quartz and feldspars, the peak shock pressure and post-shock temperature in the TiO2-II-bearing gneiss are estimated to be between 35 and 43 GPa and 300-900~C, respectively. The finding of TiO2-II in the shock-metamorphosed gneiss provides another mineral physics evidence for shock origin of the Xiuyan crater.     

Cellular prion protein imaging analysis with aptamer-labeled Ru（bpy）32＋-doped silica nanoparticles

A new type of highly selective aptamer-labeled fluorescent silica nanoparticles [Apt-tris（2,2＇-bipyri- dyl）ruthenium（II）@SiO2 NPs] were prepared through the reverse microemulsion method by using prolonged fluorescence lifetime ruthenium complexes of tris（2,2＇-bipyri- dyl）ruthenium（II） （Ru（bpy）2＋） as the source of the fluorescence for cellular prion protein imaging. Investigations showed that the newly prepared Ru（bpy）32＋@Si02 NPs possessed superior advantages of strong fluorescence, low toxicity, and easy surface modification for bioconjugation. Cell imaging experiments indicated that Apt- Ru（bpy）32＋@SiO2 NPs had great tendency to human bone marrow neuroblastoma cells （SK-N-SH cells）, since they can express large amount of prion protein on the surface of the cell, while in HeLa cells this phenomenon disappeared for the reason that HeLa cells cannot express prion proteins.     

CuFe2O4纳米粒子增敏Luminol-EDTA化学发光体系研究及应用

基于CuFe_2O_4纳米粒子能显著增强Luminol-EDTA体系的发光,首次建立了Luminol-EDTA-CuFe_2O_4 NPs化学发光新体系。紫外吸收光谱和化学发光光谱表明纳米CuFe_2O_4注入Luminol-EDTA体系后,未生成新发光物质,结合纳米CuFe_2O_4的特性,提出了CuFe_2O_4 NPs参与Luminol-EDTA体系可能的发光机理。研究发现芦丁能抑制Luminol-EDTACuFe_2O_4 NPs体系的化学发光,结合流动注射技术,将此化学发光体系应用于芦丁片中芦丁含量的测定。在优化实验条件下,芦丁浓度在2×10~(-8)~2×10~(-5) mol/L范围内芦丁浓度的对数和相对化学发光值呈线性,芦丁浓度检出限(LOD)为1.21×10~(-9) mol/L。将本方法应用于芦丁片中的芦丁含量测定,回收率为97%~102%,RSD为2.54%(c=1×10~(-7) mol/L,n=11)。     

Effect of thermal oxidation on the surface characteristics and corrosion behavior of a Ta-implanted Ti-50.6Ni shape memory alloy

A NiTi shape memory alloy (SMA) modified by Ta ion implantation was subjected to oxidation treatment in air at 723 and 873 K. Atomic force microscopy (AFM), Auger electron spectroscopy (AES), and grazing incidence X-ray diffraction (GIXRD) measurements were conducted to investigate the surface characteristics, including surface topography, elemental depth profiles, and surface phase structures. The surface roughness of the Ta-implanted NiTi increases after oxidation, and the higher the oxidation temperature is, the larger the value is. The surface of the Ta-implanted NiTi oxidized at 723 K is a nanolayer mainly composed of TiO₂/Ta₂O₅ and TiO with depressed Ni content. The Ta-implanted NiTi oxidized at 873 K is mainly covered by rutile TiO₂ in several micrometers of thickness. Potentiodynamic polarization tests indicated that the corrosion resistance of the Ta-implanted NiTi was improved after thermal oxidation at 723 K, but a negative impact was found for the Ta-implanted NiTi oxidized at 873 K.     

Synthesis,characterization, and theoretical study of N,S-codoped nano-TiO<Subscript>2</Subscript> with photocatalytic activities

Nitrogen and sulfur doped titanium dioxide photocatalysts were prepared by the sol-gel method. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-visible diffuse reflectance spectra (DRS). Photocatalytic activities of the samples were investigated on the degradation of methyl orange (MO). The effect of the dopants on the electronic structure of TiO₂ was studied by the first-principles calculations based on the density functional theory (DFT). The orbital hybridization resulted in energy gap narrowing and electronic delocalization in the crystal of doped TiO₂. Mobile electrons of varied energetic states could offer enhanced electron transfer, together with optical absorption improvement. The results show that the doping elements of N and S play a cooperative role in the modification of electronic structure, which enhances the photocatalytic performance. The experimentally observed absorption edges of N-doped TiO₂, S-doped TiO₂, and N, S-codoped TiO₂ are 420, 413, and 429 nm, respectively, which can be explained by the theoretical calculation results.     

一步法合成耐久性水基超疏水TiO2/DTMS涂层

为制备具有优异自清洁功能的耐久性水基超疏水涂层,以十二烷基三甲氧基硅烷(n-dodecyltrimethoxysilane, DTMS)为有机改性物,通过一步法在纳米TiO₂表面嫁接长链烷基官能团得到超疏水TiO₂/DTMS涂层。分析了TiO₂涂层及TiO₂/DTMS涂层的表面润湿性、形貌和化学组成,并对所得超疏水TiO₂/DTMS涂层的自清洁性能、机械及化学稳定性进行了测试。结果表明：超疏水TiO₂/DTMS涂层表面水接触角(water contact angle, WCA)达到159°;以亚甲基蓝粉末作模拟污染物,涂覆有超疏水TiO₂/DTMS涂层的玻璃具有优异的自清洁性能;经机械磨损(10 min)、酸碱液(pH=1、3、5、7、9、11、13)浸泡、高低温(−20、30、60、90、120、150 ℃)处理后超疏水TiO₂/DTMS涂层的WCA仍大于150°,表明其具有优异的机械和化学稳定性,可用于室外防污,如建筑物外墙、玻璃、太阳能电池板等。