镧掺杂介孔TiO2光催化剂的制备、表征及其光催化性能

以钛酸四正丁酯和硝酸镧为原料, 以P123为模板剂,采用模板法合成了La掺杂型介孔TiO₂光催化剂, 借助TGA-DSC、BET、XRD及UV-Vis等测试手段对样品进行了表征,并以苯酚为模型污染物考察了镧掺杂量对样品光催化活性的影响．结果表明: La掺杂介孔TiO₂光催化剂孔径分布较均匀(～10 nm),比表面积可达165 m²/g．与纯介孔TiO₂相比,经掺杂改性后的样品在紫外光区及可见光区的吸收显著增强,对光具有更高的利用率,La掺杂可显著提高介孔TiO₂的光催化活性.     

Ag-Cu纳米颗粒修饰的N掺杂TiO2纳米棒阵列及其高效光催化CO2还原应用

本文采用微纳加工方法制备了负载高密度Ag-Cu纳米颗粒的N掺杂TiO₂纳米棒阵列样品. 通过TiO₂的N掺杂,可将其吸光范围调控至与Ag纳米颗粒的等离激元吸收频率相匹配的波段,从而实现复合材料中肖特基结与共振能量转移过程的协同作用. 与此同时,Cu纳米颗粒可以为CO₂还原提供活性位点. 在全谱光照射下,复合样品光催化CO₂还原的活性显著提高,CH₄生成速率可达720 μmol·g^-1·h^-1.     

纤维状TiO2/Bi2O3光催化剂的制备及其光催化性能

以C₁₆H₃₆O₄Ti和Bi(NO₃)·5H₂O为原料,以棉花纤维为生物模板,合成了系列纤维状TiO₂/Bi₂O₃光催化剂．采用XRD、SEM、UV-Vis等测试技术对样品的相结构、形貌和吸光性能等进行了表征分析．结果表明,样品中的Bi₂O₃为单斜相和四方相共存的混晶,纤维长度达到毫米级,     

臭氧修饰(001)晶面TiO2纳米片及其光催化降解甲苯研究

本文系统研究了臭氧修饰对(001)主导晶面锐钛矿型TiO₂光催化剂降解甲苯性能的影响. 利用自行搭建的光催化VOCs降解装置对催化剂光降解甲苯的性能进行了测试. 通过多种表征手段,结合原位DRIFTS和DFT计算研究了臭氧表面修饰及甲苯吸附和降解机理. 结果表明,用臭氧进行表面修饰可以显著提高(001)主导晶面TiO₂光催化降解甲苯的性能. (001)晶面上丰富的5c-Ti不饱和配位是臭氧分子的吸附位点,其解离后形成的Ti-O键与H₂O分子结合,在表面生成大量孤立的Ti_5c-OH. Ti_5c-OH 是甲苯分子的吸附位,它的形成显著提高了对甲苯分子的吸附能力. 在光照下Ti_5c-OH与光生空穴结合能形成·OH自由基. 通过臭氧解离产生的O₂也可以与光生电子结合形成超氧自由基. 这些具有强氧化性活性自由基的形成促进了对气相甲苯的光催化降解速率.     

硼(氮、氟)掺杂对TiO2纳米颗粒光学性能的影响

利用X射线衍射谱、拉曼光谱和紫外-可见光吸收光谱研究了硼(氮、氟)掺杂对TiO₂纳米颗粒光学性能的影响.X射线衍射谱和拉曼光谱结果表明,掺硼(氮、氟)对TiO₂纳米颗粒的锐钛矿相晶体结构无明显影响,而其锐钛矿晶格出现畸变(c/a值增大),这被归因于掺杂原子对TiO₂纳米颗粒表面氧原子缺位沿晶格c轴方向的占据.另外,掺硼(氮、氟)TiO₂纳米颗粒吸收带红移与TiO相似文献   

H2O2水热合成双峰介孔硅MCM-48球

在温和的条件下,通过H₂O₂水热处理预合成的MCM-48,得到了有序的双峰介孔硅MCM-48球． 结果表明H₂O₂对于同时去除有机模板剂及形成双峰介孔硅MCM-48球具有重要的作用．采用XRD、TEM、FT-IR和N₂吸附-解吸等方法对双峰介孔MCM-48材料进行了表征,对双峰介孔MCM-48的形成机理也进行了探讨．     

多孔TiO2/Al/SiO2纳米复合结构的紫外光吸收特性研究

在SiO₂玻璃衬底上用脉冲激光沉积(PLD)技术,分别沉积Ti和Ti/Al膜,经电化学阳极氧化成功制备了多孔TiO₂/SiO₂和TiO₂/Al/SiO₂纳米复合结构. 其中TiO₂薄膜上的微孔阵列高度有序,分布均匀. 实验研究了Al过渡层对多孔TiO₂薄膜光吸收特性的影响. 结果表明：无Al过渡层的多孔TiO₂薄膜其紫外吸收峰在27     

介孔SiO2纳米棒的制备及其表面锚接金纳米粒子

 以正硅酸乙酯为硅源,十六烷基三甲基溴化铵为模板剂,聚乙二醇为分散剂,采用溶胶-凝胶法制备出SiO₂纳米粒子,应用透射电镜、扫描电镜、X射线衍射仪、红外光谱仪和X射线能谱仪研究了粒子的性能。结果表明：所得产物是具有周期性规则介孔的棒状粒子,长径比随着硅源、模板剂和分散剂浓度的降低而减小;向反应体系中引入乙醇,随着乙醇与水的体积比例的增加,粒子由棒状向球状转变,进而形成不规则絮状凝聚体。用硅烷化技术对SiO₂纳米棒表面进行修饰后吸附平均粒径3.7 nm的金种子,再用多轮生长法使种子长大,经过30轮生长,种子平均粒径增大至59 nm,得到了SiO₂-Au复合纳米体系。透射电镜和紫外-可见分光光度计分析结果表明：金纳米粒子锚接在SiO₂纳米棒表面的某些点位,呈分散分布;复合体系表现出强烈的金的表面等离子体共振吸收峰,该峰随着金粒子的粒径增大,在500~700 nm波段内红移。     

纳米TiO2多孔膜的微结构对染料敏化纳米薄膜太阳电池性能的影响

采用溶胶-凝胶方法,在不同的实验条件下获得平均粒径从15到25nm左右的纳米TiO２2颗粒.利用这些颗粒制备出的纳米多孔薄膜,应用于染料敏化纳米薄膜太阳电池. 通过x射线 衍射仪分析,得到TiO２₂颗粒的晶相以及晶粒度大小,用透射电子显微镜观察 了纳米TiO２₂颗粒的形貌和尺寸.应用于太阳电池的纳米TiO２₂多 孔膜,经基于布朗诺尔-埃米特-泰 勒（BET）的多层吸附理论的比表面积测试和孔径分布测试,获得了多孔膜的微关键词：溶胶-凝胶法2')\" href=\"#\">纳米TiO２₂染料敏化太阳电池     

TiO2 Wedgy Nanotubes Array Flims for Photovoltaic Enhancement

In this study, TiO₂ wedgy nanotubes with rectangular cross-sections were fabricated on transparent conductive substrates by using TiO₂ nanorods as the precursor via the anisotropic etching route. TiO2 nanotubes with V-shaped hollow structure and the special crystal plane exposed on the tube wall possess nature of high surface area for more dye molecules absorption, and the strong light scattering effects and dual-channel for effective electron transport of the TiO₂ V-shaped nanotubes based dye-sensitized solar cell exhibit a remarkable photovoltaic enhancement compared with the TiO₂ nanorods. The photoanode based on our V-shaped TiO₂ nanotubes with a length of 1.5 μm show a 123% increase of the dye loading and a 182% improvement in the overall conversion efficiency when compared with 4 μm rutile TiO₂ nanorods photoanode.     

An investigation of DNA-like structured dye-sensitized solar cells

This paper reports a 3D DNA-like structured dye-sensitized solar cell (DSSC) with all-Ti substrates. A self-organized TiO₂ nanotubular arrays layer was directly grown on the photoanode surface by electrochemical anodization. Compared with the traditional flat-type DSSC, the DNA-like DSSC showed superiority of light utilization due to its symmetrical double-helix structure. Different thickness of the nanotubular arrays layers were investigated to find their influence on the cell’s photovoltaic parameters, and the cell with a 15.3 μm layer exhibited the highest P_max, about 0.49 mW. The series–parallel connection characteristics of the DNA-like DSSCs reveal that the total voltage and the total short current equalled the sum of each cell’s in series and in parallel, respectively. It is anticipated that the novel DNA-like structured DSSCs have great application potential in larger modules using integrated circuit.     

电沉积处理与染料敏化纳米薄膜太阳电池的优化

采用阳极氧化水解法对染料敏化纳米TiO₂薄膜太阳电池的光阳极进行不同方式的电沉积优化处理.借助x射线衍射仪对处理后的样品进行分析,通过超高分辨率场发射扫描电子显微镜对导电玻璃以及电沉积处理前后纳米多孔薄膜表面进行了粒径和形貌的扫描.染料敏化太阳电池实验测试结果表明,电沉积处理和修饰后可以明显提高光生电子的收集率,增大短路电流密度,提高电池效率.关键词：2')\" href=\"#\">纳米TiO₂染料敏化电沉积太阳电池     

Cocktail effect of Fe2O3 and TiO2 semiconductors for a high performance dye-sensitized solar cell

The bi-semiconductors of TiO₂ and Fe₂O₃ were used as a photoelectrode material in a high performance dye-sensitized solar cell due to cocktail effects from the two conduction bands. The size of the semiconductors was reduced by using a paint shaker to enlarge the contact area of the semiconductor with the dye or electrolyte. The fill factor and the efficiency of the prepared dye-sensitized solar cell were improved by over 16% and 300%, respectively; these parameters were measured from a current-voltage curve that was based on the effects of the Fe₂O₃ co-semiconductor and the size reduction. A mechanism is suggested wherein the conduction band of Fe₂O₃ works to prohibit the trapping effects of electrons in the conduction band of TiO₂. This result is attributed to the prevention of electron recombination between electrons in the TiO₂ conduction band with dye or electrolytes. The mechanism is suggested based on impedance results, which indicate improved electron transport at the interface of the TiO₂/dye/electrolyte.     

Formation of single-crystalline TiO2 nanomaterials with controlled phase composition and morphology and the application in dye-sensitized solar cell

Single-crystalline TiO₂ nanomaterials with controlled phase composition and morphology were synthesized by hydrothermal transformation of H-titanate nanotubes under different pH. Rutile rectangle nanorods with two four-side tapered tips were produced at pH of 0, whereas anatase nanoparticles with mainly of rhombic shape were obtained at pH from 2 to 7 and their average particle size increased with pH. The transformation mechanisms at different pH were discussed. The single-crystalline anatase nanoparticles obtained at pH of 2 had ca. 12 nm in average particle size, and the powder possessed as large as 112 m²/g specific surface areas; the conversion efficiency of the dye-sensitized solar cell based on the nanoparticles was increased by over 40% as compared with that of the cell based on P25.     

In situ Radical Copolymerization in Presence of Surface‐Modified TiO2 Nanoparticles: Influence of a Double Modification on Properties of Unsaturated Polyester (UP) Nanocomposites

In the preparation of nanocomposites, there is competition between the dispersion of nanoparticles and the formation of agglomerates. In this study, radical copolymerization of ethyl acrylate and methyl methacrylate initiated by 2,2‐azobis (isobutyro) nitrile (AIBN) was performed, in the presence of titanium oxide (TiO₂) nanoparticles modified in a new approach; a good dispersion of the nanoparticles in the unsaturated polyester (UP) matrix was obtained. The TiO₂ nanoparticles were exposed to 3‐(methacryloxy) propyl trimethoxy silane as the coupling agent. The presence of coupling agent‐grafted TiO₂ nanoparticles in the copolymerization process resulted in the formation of a polymeric layer on the surface of the TiO₂ nanoparticles (doubly modified‐TiO₂). The grafting of coupling agent molecules and consequently copolymer macromolecular chains onto the surface of TiO₂ nanoparticles was investigated using Fourier transform infrared (FTIR) analysis. It found that the formation of an acrylate layer on the surface of nanoparticles was successful. Then, unsaturated polyester (UP)/TiO₂ nanocomposites were prepared. The morphology was studied using transmission electron microscopy (TEM). Mechanical properties and ultraviolet visible (UV/VIS) spectroscopy of various samples, including the doubly modified‐TiO₂ nanoparticles, with different nanoparticle inclusions and the unmodified‐TiO₂ nanoparticles, were also investigated. The results showed the doubly modified‐TiO₂ nanoparticles, compared to those of unmodified‐TiO₂, had better nanoparticle dispersion causing improvement in the mechanical properties and UV shielding.     

Low resistance dye-sensitized solar cells based on all-titanium substrates using wires and sheets

Low resistance dye-sensitized solar cells (DSSCs) based on all-titanium substrates were proposed in this paper. To minimize the internal resistance of DSSCs, the titanium wires and titanium sheets were used as the substrates of the photoanode and the counter electrode, respectively. Compared with the FTO substrate, titanium wires could absorb much diffused light by back reflection since the reflectivity in the titanium sheet was highly increased up to 53.12%. Furthermore, the transmittance of the front cover was increased by 13.2% using the super white glass instead of FTO substrate. The thickness of TiO₂ thin film coated on titanium wire was optimized to achieve a high cell performance. The efficiency of 5.6% for the cell was obtained with a J_sc of 15.41 mA cm⁻², V_oc of 0.59 V, and FF of 0.62. The results showed that the titanium-based DSSCs had superiority for producing the large-scale DSSCs without metal grid line.