改进型溶胶-凝胶法制备粒径可调高染料吸附量TiO2微球及其在染敏电池光散射层中的应用

利用改进型的溶胶-凝胶法,制得了由锐钛矿相纳米颗粒组成的TiO2多孔微纳小球。通过调节前驱物浓度,合成出粒径可控的尺寸分别为100,175,225,475 nm的TiO2微纳小球,并通过电泳沉积法将合成出的小球作为光散射层引入到染料敏化太阳电池(DSSC)中。由于这种微纳小球在具备良好的光散射性能的同时也具备较高的染料吸附量,因此相较于基于纳米颗粒的单层结构的DSSC拥有更高的光电转换效率。通过比较分析,粒径尺寸为475 nm的微球作为光散射层的DSSC光电转换效率可以达到6.3%,较之于基于纳米颗粒的DSSC提高了30%。     

改进型溶胶-凝胶法制备粒径可调高染料吸附量TiO2微球及其在染敏电池光散射层中的应用

利用改进型的溶胶-凝胶法, 制得了由锐钛矿相纳米颗粒组成的TiO₂多孔微纳小球。通过调节前驱物浓度, 合成出粒径可控的尺寸分别为100, 175, 225, 475 nm的TiO₂微纳小球, 并通过电泳沉积法将合成出的小球作为光散射层引入到染料敏化太阳电池(DSSC)中。由于这种微纳小球在具备良好的光散射性能的同时也具备较高的染料吸附量, 因此相较于基于纳米颗粒的单层结构的DSSC拥有更高的光电转换效率。通过比较分析, 粒径尺寸为475 nm的微球作为光散射层的DSSC光电转换效率可以达到6.3%, 较之于基于纳米颗粒的DSSC提高了30%。     

双层结构CeO2光阳极在染料敏化太阳能电池中的应用

利用水热法合成核壳结构Au@SiO₂@CeO₂纳米微球,制备了一系列双层结构复合光阳极并应用于染料敏化太阳能电池(DSSC)。研究表明：当CeO₂纳米微球和核壳结构Au@SiO₂@CeO₂纳米微球应用于DSSC光阳极散射层时,电池的光电转化效率有了显著提高。相对于纯TiO₂(P25)光阳极,P25/CeO₂纳米球光阳极电池的DSSC光电性能提高了15.3%,P25/Au@SiO₂@CeO₂纳米球光阳极电池的光电性能提高了27.9%。DSSC光电性能的提高主要归因于2个方面：一方面,Au纳米粒子的表面等离子体共振效应有效提高了光阳极薄膜的光散射效应。另一方面,CeO₂具有较高的染料负载能力,核壳球形结构具有较高的比表面积,增强了光的散射效应,提高了电子传输能力。     

双层结构CeO2光阳极在染料敏化太阳能电池中的应用

利用水热法合成核壳结构Au@SiO₂@CeO₂纳米微球,制备了一系列双层结构复合光阳极并应用于染料敏化太阳能电池(DSSC)。研究表明：当CeO₂纳米微球和核壳结构Au@SiO₂@CeO₂纳米微球应用于DSSC光阳极散射层时,电池的光电转化效率有了显著提高。相对于纯 TiO₂ (P25)光阳极,P25/CeO₂纳米球光阳极电池的 DSSC 光电性能提高了 15.3%,P25/Au@SiO₂@CeO₂纳米球光阳极电池的光电性能提高了27.9%。DSSC光电性能的提高主要归因于2个方面：一方面,Au纳米粒子的表面等离子体共振效应有效提高了光阳极薄膜的光散射效应。另一方面,CeO₂具有较高的染料负载能力,核壳球形结构具有较高的比表面积,增强了光的散射效应,提高了电子传输能力。     

染料敏化La~(3+)掺杂的TiO_2纳晶薄膜制备及其光电性能

采用溶胶-凝胶法制备出La3+掺杂的TiO2纳米粉体材料,通过料浆喷涂工艺制得掺杂La3+的TiO2薄膜并将其以N719染料敏化制成染料敏化太阳能电池(DSSC)。以X射线衍射(XRD)、扫描电镜(SEM)和DSSC测试系统对制得的La3+掺杂的TiO2纳米粉体材料、相应的La3+掺杂的TiO2薄膜以及制成的DSSC分别进行测试表征,研究了La3+掺杂对TiO2晶型和染料敏化太阳能电池性能的影响。XRD测试结果表明,La3+的掺杂改善了TiO2的颗粒分布;电池的测试结果说明,La3+掺杂量为0.5%,煅烧温度为450℃时制备的纳米TiO2膜DSSC电池性能最佳,光电转换效率达1.926%。     

TiO2/SnO2复合空心球在染料敏化太阳能电池中的应用

采用模板辅助法制备了SnO2/TiO2复合空心球,样品直径为1.5~4.0μm,比表面积达到了92.9 m^2·g^-1,复合空心球表现出优越的光散射性能.以这种复合空心球作为染料敏化太阳能电池的光阳极,电池的光电转换效率可达到7.72%,高于SnO2微米球(2.70%)和TiO2微米球(6.26%).此外,以锐钛矿型TiO2纳米晶作为底层,SnO2/TiO2复合空心球作为光散射层制备的双层结构光阳极,电池光电转换效率进一步提升至8.43%.     

TiO2薄膜优化对染料敏化太阳电池性能的影响

纳米TiO2多孔薄膜微结构对染料敏化太阳电池(DSC)光伏性能有很大的影响。本文采用不同实验和测试方法研究和分析了溶胶-凝胶法制备纳米TiO2颗粒时的热处理温度、TiO2多孔薄膜厚度、纳米TiO2大颗粒光散射、TiCl4溶液处理和电沉积致密TiO2层对纳米多孔薄膜电极和染料敏化太阳电池光伏性能的影响,得到了最佳的优化条件,为纳米TiO2薄膜材料的批量化制作打下了良好基础。     

TiO2纳米片/巢状分级结构纳米阵列薄膜的制备及其在染料敏化太阳能电池中的应用

采用水热合成法在氟掺杂二氧化锡(FTO)导电玻璃基底上得到TiO2纳米阵列薄膜,并进一步通过NaOH溶液水热处理制备了由巢状纳米阵列及纳米片覆盖层构成的TiO2纳米阵列分级结构一体化薄膜.采用场发射扫描电镜(FE-SEM),X射线衍射(XRD),紫外-可见(UV-Vis)漫反射光谱和吸收光谱技术对TiO2薄膜的结构和性质进行表征.FE-SEM结果表明:分级结构TiO2薄膜膜厚为1.5μm,薄膜由一层纳米片覆盖层(约0.2μm高)和一层巢状纳米阵列层(约1.3μm高)组成.XRD谱图表明TiO2薄膜为锐钛矿相.UV-Vis光谱显示分级结构TiO2薄膜具有较强的光捕获能力和染料吸附能力.TiO2纳米片/巢状分级结构纳米阵列薄膜作为光阳极,可有效地提高染料敏化太阳能电池的光电转换效率,其短路电流(Jsc)为7.79mA·cm-2,开路电压(Voc)为0.80V,填充因子(FF)为0.40,光电转换效率(η)为2.48%,其光电转换效率较TiO2纳米阵列薄膜提高了近10倍.     

静电纺丝-碱热法制备高活性由纳米片组装的TiO2纳米纤维（英文）

半导体光催化有望解决日益严峻的环境污染与能源危机,因而得到广泛重视.纳米TiO2因为其强的氧化能力和良好的(光)化学稳定性与生物相容性,成为了最受欢迎的半导体光催化材料.到目前为止,材料科学家们制备了多种形貌的TiO2光催化材料,如纳米棒(线)、纳米片和空心微球等.作为染料太阳能电池的光阳极材料,小颗粒尺寸的纳米TiO2具有大的比表面积,有利于敏化剂的吸附,从而增强太阳能电池的光电转换性能.但是尺寸太小的TiO2颗粒不利于光散射,导致入射的太阳光直接穿透光阳极薄膜而不利于吸收和利用太阳光.为了解决敏化剂吸附和增强光散射这对矛盾,本文设计制备了由纳米片组装的TiO2纳米纤维:(1)首先通过静电纺丝法制备TiO2纳米纤维前躯体;(2)将TiO2纳米纤维前驱体在500°C焙烧,去除有机物,得到晶化度良好的由纳米颗粒组装的TiO2纳米纤维;(3)将TiO2纳米纤维进行NaOH碱热处理,使TiO2纳米颗粒转化成钛酸盐纳米片,然后经历酸洗和焙烧,得到由纳米片组装的TiO2纳米纤维.染料敏化太阳能电池的性能测试结果显示,碱热2.5 h所得TiO2样品的光阳极薄膜的光电转化效率提升了2.3倍;同时,利用丙酮光催化分解的活性来评价纳米纤维的光催化活性,发现碱热2.5 h所得纳米纤维上光催化降解丙酮的活性提升了3.1倍.结构表征结果显示,随着碱热时间的延长,从纤维表面生长出来的纳米片逐渐变长,催化剂的比表面积和孔容不断增加.大的比表面积有利于底物的吸附,纳米片结构有利于增强光散射,通过延长光程增强对光的利用效率,从而提升纳米纤维的光活性.光电流测试的结果显示,与碱热前的TiO2纳米纤维相比,碱热后的TiO2纳米纤维光电流显著增强,这是由于纳米片结构减小了扩散距离,有利于光生载流子快速转移到催化剂表面,引发丙酮的光催化氧化.     

染料敏化太阳电池中双层结构TiO2薄膜空间的电子分布与接触界面转移过程

采用电化学阻抗谱(EIS)研究了双层结构TiO2薄膜的电子积累和与电解液接触界面的电子转移过程. 通过制备纳米颗粒单层和纳米颗粒/亚微米颗粒双层2种不同微结构的TiO2薄膜电极, 对其电容分布、 局域态密度、 薄膜内部电子传输和固/液界面电子转移过程进行了研究. 分析了纳米颗粒/亚微米颗粒双层结构电极对染料敏化太阳电池(DSC)性能的影响. 结果表明, 一定数量的电子会积累在亚微米颗粒层中引起薄膜电极化学电容的增加. 在纳米颗粒层上端覆盖亚微米颗粒后降低了界面复合电阻, 但对薄膜电极的传输性能影响较小. 因此在筛选和制备DSC散射层材料时除应具有良好的光散射性能外, 还应考虑材料的化学电容和界面转移电阻等因素.     

Synthesis of Uniform Layered Protonated Titanate Hierarchical Spheres and Their Transformation to Anatase TiO2 for Lithium‐Ion Batteries

Layered protonated titanates (LPTs), a class of interesting inorganic layered materials, have been widely studied because of their many unique properties and their use as precursors to many important TiO₂‐based functional materials. In this work, we have developed a facile solvothermal method to synthesize hierarchical spheres (HSs) assembled from ultrathin LPT nanosheets. These LPT hierarchical spheres possess a porous structure with a large specific surface area and high stability. Importantly, the size and morphology of the LPT hierarchical spheres are easily tunable by varying the synthesis conditions. These LPT HSs can be easily converted to anatase TiO₂ HSs without significant structural alteration. Depending on the calcination atmosphere of air or N₂, pure anatase TiO₂ HSs or carbon‐supported TiO₂ HSs, respectively, can be obtained. Remarkably, both types of TiO₂ HSs manifest excellent cyclability and rate capability when evaluated as anode materials for high‐power lithium‐ion batteries.     

Large‐Scale Production of Hierarchical TiO2 Nanorod Spheres for Photocatalytic Elimination of Contaminants and Killing Bacteria

We report a facile non‐hydrothermal method for the large‐scale production of hierarchical TiO₂ nanorod spheres for the photocatalytic elimination of contaminants and killing bacteria. Crescent Ti/RF spheres were prepared by deliberately adding titanium trichloride (TiCl₃) to the reaction of resorcinol (R) and formaldehyde (F) in an open reactor under heating and stirring. The hierarchical TiO₂ nanorod spheres were obtained by calcining the crescent Ti/RF spheres in a furnace in air to burn off the RF spheres. This method has many merits, such as large‐scale production, good crystallisation of TiO₂, and good reproducibility, all of which are difficult to realise by conventional hydrothermal methods. The calcination temperature plays a significant role in influencing the morphology, crystallisation, porosity, Brunauer–Emmett–Teller (BET) specific surface area, and hierarchy of the TiO₂ nanorod spheres, thus resulting in different photocatalytic performances under UV light and solar light irradiation. The experimental results have demonstrated that the hierarchical TiO₂ nanorod spheres obtained after calcination of the crescent Ti/RF spheres at different temperatures displayed similar photocatalytic activities under irradiation with UV light. We attribute this to a balance of opposing effects of the investigated factors. A higher calcination temperature leads to greater light absorption capability of the TiO₂ nanorod spheres, thus resulting in higher photocatalytic antibacterial activity under solar light irradiation. It is also interesting to note that the hierarchical TiO₂ nanorod spheres displayed intrinsic antibacterial activity in the absence of light irradiation, apparently because their sharp outward spikes can easily pierce and penetrate the walls of bacteria. In this study, the sharpest hierarchical TiO₂ nanorod spheres were obtained after calcination at 500 °C, and these exhibited the highest antibacterial activity without light irradiation. A higher calcination temperature proved detrimental to the sharpness of the TiO₂ nanorods, thus reducing their intrinsic antibacterial activity.     

微观形貌可控TiO2的制备及其光解水产氢性能

通过简单的沉淀、水热、溶剂热和溶胶凝胶法分别制备出实心球（s-TiO₂）、空心球（h-TiO₂）、纳米管（a-TNT）和介孔形状（m-TiO₂）的锐钛矿晶型结构TiO₂光催化材料。采用HRTEM、FESEM、XRD、UV-Vis、N₂吸-脱附和光解水制氢反应等对催化材料的微观表面结构、光吸收性能以及不同形貌光催化剂的光解水制氢的性能对比研究。结果表明：s-TiO₂具有最高的光催化活性,主要归功于s-TiO₂独特的微观形貌结构所致,s-TiO₂是由亚微晶颗粒组成的介孔状实心球,亚微晶粒径相比较其它形貌的材料要小,有利于光生载流子的迁移,抑制电子-空穴对的体相复合,导致活性提高。同时,晶化过程用于传质通道的无序微孔可以束缚用作牺牲剂的CH₃OH分子,使得空穴快速被牺牲剂消耗,减少与电子复合。     

微观形貌可控TiO2的制备及其光解水产氢性能

通过简单的沉淀、水热、溶剂热和溶胶凝胶法分别制备出实心球(s-TiO_2)、空心球(h-TiO_2)、纳米管(a-TNT)和介孔形状(mTiO_2)的锐钛矿晶型结构TiO_2光催化材料。采用HRTEM、FESEM、XRD、UV-Vis、N2吸-脱附和光解水制氢反应等对催化材料的微观表面结构、光吸收性能以及不同形貌光催化剂的光解水制氢的性能对比研究。结果表明:s-TiO_2具有最高的光催化活性,主要归功于s-TiO_2独特的微观形貌结构所致,s-TiO_2是由亚微晶颗粒组成的介孔状实心球,亚微晶粒径相比较其它形貌的材料要小,有利于光生载流子的迁移,抑制电子-空穴对的体相复合,导致活性提高。同时,晶化过程用于传质通道的无序微孔可以束缚用作牺牲剂的CH3OH分子,使得空穴快速被牺牲剂消耗,减少与电子复合。     

p-Aminophenylacetic acid-mediated synthesis of monodispersed titanium oxide hybrid microspheres in ethanol solution

Monodispersed TiO₂ hybrid microspheres were prepared via the hydrolysis of titanium isopropoxide (TTIP) in ethanol solution containing p-aminophenylacetic acid (APA). The effects of the APA:TTIP molar ratio, water content, reaction time and reaction temperature on the morphology of the resultant spheres were investigated. The products were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. It was demonstrated that the diameters of the resultant TiO₂ spheres could be tuned in the range of 380–800 nm by changing the APA:TTIP molar ratio (1:3 to 3:1) and water content (1–3 v/v%) in the reaction medium, and that increasing the APA:TTIP molar ratio led to larger TiO₂ hybrid spheres while increasing the water content decreased their size. The loading content of APA in the hybrid spheres could reach 20 wt.% as they were prepared with the APA:TTIP ratio of 3:1. The possible formation mechanism of the hybrid spheres was also investigated. It was found that APA slowed down the hydrolysis rate of the titanium precursor so that resulted in the formation of the TiO₂ spheres. In addition, the APA present in TiO₂ spheres acted as a reducing agent to in situ convert HAuCl₄ into metallic Au on the surface of the TiO₂ spheres. The catalytic activity of the resultant Au/APA–TiO₂ composite was examined using transfer hydrogenation of phenylacetone with 2-propanol, and it was indicated that the catalyst displayed high efficiency for this reaction.     

TiO2微球的合成及其作为散射层在量子点敏化太阳能电池中的应用

以十六烷基三甲基溴化铵（CTAB）为模板剂,通过TiCl₄在乙醇水溶液中的直接水解,制备了介孔TiO₂微球. X射线衍射（XRD）结果表明所制备的微球晶型为金红石,扫描电镜（SEM）结果显示微球的直径大约为700 nm,由粒径约为16 nm的小颗粒堆积而成. 通过刮涂法制备了在TiO₂小颗粒层上涂覆有作为散射层的TiO₂微球和未涂覆微球的薄膜. 并通过化学浴沉积（CBD）的方法在膜上生长CdS/CdSe量子点,得到了量子点敏化太阳能电池（QDSCs）. 紫外吸收和漫反射结果表明,这种微球结构有利于量子点的沉积,具有较强的光散射作用,有效地增加了光线的收集,从而提高了电池的光电流,最终得到了4.5%的光电转换效率,比不加散射层的电池的效率高27.7%,也比利用传统散射层（由20 nm TiO₂ 小颗粒和400 nm TiO₂ 固体颗粒组成）的电池效率高10.2%. 我们把电池效率的提升归因于较强的光散射作用和较长的电子寿命.     

Synthesis of uniform layered protonated titanate hierarchical spheres and their transformation to anatase TiO2 for lithium-ion batteries

Layered protonated titanates (LPTs), a class of interesting inorganic layered materials, have been widely studied because of their many unique properties and their use as precursors to many important TiO(2)-based functional materials. In this work, we have developed a facile solvothermal method to synthesize hierarchical spheres (HSs) assembled from ultrathin LPT nanosheets. These LPT hierarchical spheres possess a porous structure with a large specific surface area and high stability. Importantly, the size and morphology of the LPT hierarchical spheres are easily tunable by varying the synthesis conditions. These LPT HSs can be easily converted to anatase TiO(2) HSs without significant structural alteration. Depending on the calcination atmosphere of air or N(2), pure anatase TiO(2) HSs or carbon-supported TiO(2) HSs, respectively, can be obtained. Remarkably, both types of TiO(2) HSs manifest excellent cyclability and rate capability when evaluated as anode materials for high-power lithium-ion batteries.     

混晶海胆状TiO2空心球多级结构的制备及其对亚甲基蓝的光催化降解

用简单的无模板水热法可控合成了金红石相锥刺和锐钛矿相空心球的海胆状TiO2多级结构。研究了制备介质pH值和反应时间对形貌的影响。空心球上锥刺的密度可以通过改变反应条件加以调控。对海胆状TiO2多级结构可能的形成机理进行了研究。将不同锥刺密度的TiO2空心球应用于亚甲基蓝降解的光催化研究,结果表明低锥刺密度的TiO2空心球的光催化效果优于P25-TiO2,更优于锥刺多和无锥刺的光滑TiO2空心球。