纳米TiO2膜电极的制备及其电催化性能

采用溶胶-凝胶法制备TiO2溶胶,以钛酸丁酯为前驱物和二乙醇胺为催化剂,研究了不同条件下(水量、溶剂量、催化剂量、温度)TiO2溶胶的制备过程,得出了最佳工艺条件,采用此溶胶制备了纳米膜电极,用XRD、拉曼光谱进行表征,用循环伏安法分析了其电催化性能,结果表明其电催化性质与晶型有关。     

TiO2纳米晶多孔薄膜太阳能电池的制备

利用溶胶-凝胶法制备TiO2纳米晶多孔薄膜，采用天然染料作为光敏化剂，采用I^-和I^3-作为电解质来制备太阳能电池。     

敏化对微弧氧化TiO2膜光催化性能的影响

采用微弧氧化法以磷酸钠为电解液在钛片上制备TiO2膜,通过对苯胺废水的光催化降解率来表征TiO2膜的光催化性能,采用溶胶-凝胶和敏化处理对TiO2膜进行改性。实验结果表明:用溴甲酚绿敏化溶胶-凝胶法负载两次的TiO2膜,当溴甲酚绿敏化剂的质量浓度为20 mg/L,pH为5,敏化时间为16 h,TiO2膜的光催化效率达到40.6%。     

纳米多孔TiO2光触媒的制备与性能研究

本论文采用溶胶-凝胶技术。以钛酸四丁酯Ti（OC4H9）4为前驱体,加入聚乙二醇（polyethyleneglycol,PEG）作为模板剂。在玻璃基片上制备了纳米TiO2多孔薄膜。通过SEM观察了多孔薄膜的表面形貌,通过XRD的测试分析表征了材料的结构。探讨了样品在溶胶-凝胶及烧结过程中的物理化学变化。测定了氧化钛的晶相。利用甲基橙溶液来测定纳米TiO2薄膜的催化降解性能。实验结果表明：通过调整H2O／Ti（OC4H9）4摩尔比及PEG的添加量可得到孔径范围在50—500nm且孔径可调的多孔氧化钛纳米薄膜。且铜成的薄膜具有很好的催化效果。     

纳米TiO2的制备及其光催化性能的研究

采用改进的溶胶-凝胶(sol-gel)方法,以钛酸四丁酯(TB)和苯甲酸为主要原料,通过溶剂热处理得到纳米级TiO2.以XRD、Raman、TEM和BET对样品的晶型和形貌进行了表征.结果表明,改进的sol-gel法制备得到的TiO2是结晶性很好的锐钛矿晶型TiO2,具有较大的比表面积.以偶氮染料甲基橙(MO)水溶液为目标降解物,考察了TiO2催化剂在紫外光照射下的光催化性能.实验结果显示,TiO2催化剂60 min就可以将MO彻底降解.     

电沉积TiO2纳米晶薄膜及其光电性能研究

采用阴极电沉积法在导电玻璃基体上制备了TiO2薄膜.运用扫描电子显微镜、X-射线能量散射分析仪和X-射线衍射仪对TiO2薄膜的形貌和结构进行了分析.以N719染料敏化的TiO2薄膜为阳极,0.5 mol/L KI和0.05 mol/L I2的乙氰和乙烯碳酸酯的混合溶液为电解液,碳电极为阴极,组成太阳能电池,通过电流-电压曲线研究了太阳能电池的性能.结果表明:TiO2薄膜的晶型为锐钛矿,其晶粒d平均为28.8 nm.太阳能电池的U开路为0.513 V,J短路为22.8 A/m2,填充因子为0.392,光电转换效率为0.466%.     

CdS敏化TiO2薄膜的制备和光电转换性质的研究

本采用溶胶-凝胶法在玻璃基片上涂敷,制备了掺杂CdS微晶的TiO2复合薄膜,采用XRD、TEM研究了薄膜的物相及结构特征;UV-VIS-NIR谱研究了薄膜的光吸收特性;光生电流谱研究了薄膜的光电转换效率,结论表明：CdS的掺入有利于薄膜对可见光吸收的增强,从而提高其采光效率及光电转移效率。     

掺铈纳米TiO2的制备及其对光催化性能的影响

为改进和提高纳米二氧化钛光催化剂的催化性能,利用硝酸铈及钛酸丁酯为主要原料,通过溶胶-凝胶法制备纳米掺铈二氧化钛光催化剂,并用TGA、XRD、BET等方法对粒子进行表征,并通过其催化降解亚甲基兰来研究其催化活性影响.结果表明：铈掺杂法制备的纳米级二氧化钛,降低了粒子半径,提高了比表面积和催化活性;在较低的浓度范围内,随着掺杂量增加,光催化活性增加,2.3%TiO2光催化活性最高.     

敏化纳米晶TiO2太阳电池的光电转换研究

该文对光电化学太阳能电池的发展历程和工作原理进行了探讨,并指出了该电池存在的一些主要问题,介绍了通过复合掺杂可以提高TiO2光阳极的光电转换效率,指出用导电聚合物代替染料敏化修饰纳米晶网络电极,已成为提高太阳能电池的稳定性和光电转换效率的研究热点。     

TiO2薄膜的制备方法及其对染料敏化太阳电池性能的影响

采用溶胶-凝胶、浆体涂敷、磁控溅射等方法制备了二氧化钛单层以及多层膜．通过透射电镜、扫描电镜以及X射线衍射实验分析了不同薄膜的结构．通过比较不同薄膜制作的染料敏化太阳电池性能探讨了薄膜结构的影响．实验所获得的电池开路电压可达708mV，短路电流可达13．26mA(电池面积为1．8cm^2)．     

碳纳米管/纳米TiO2-聚苯胺复合膜电极的制备及电化学性能

在含有0.2 mol·L^-1苯胺的0.5 mol·L^-1 H2SO4溶液中;采用循环伏安法（CV）;以扫描速度50 mV·s^-1;扫描电位为-0.1～0.9 V;在碳纳米管/纳米TiO₂（CNT/nanoTiO₂）膜电极上实现了苯胺的电化学聚合;通过CV法和电化学阻抗谱（EIS）并结合电子扫描显微镜和红外谱图对制备的碳纳米管/纳米TiO₂-聚苯胺（CNT/nanoTiO₂-PAn）复合膜电极的电化学性质和结构进行了表征;同时研究了复合膜电极对抗坏血酸（AH₂）的电催化性能;发现该复合膜电极对抗坏血酸的氧化具有较高的电催化活性。     

水热法制备CdSe和PbSe共负载TiO2纳米带复合材料

采用两步水热合成过程制得了CdSe或/和PbSe负载的TiO2纳米带复合材料。用XRD、SEM、TEM、UV-Vis吸收和FTIR等测试技术对产物进行了一系列表征。结果表明,六方相CdSe粒子或/和立方相PbSe粒子直接负载在四方相锐钛矿型TiO2纳米带表面,其中呈近球形CdSe粒子的粒径主要在100~400 nm,而呈近立方体形PbSe粒子的边长主要在300~1 000 nm。CdSe和PbSe共负载TiO2纳米带复合材料在可见光区域有强的光吸收。由FTIR谱图推断,在复合材料载体TiO2纳米带结构中掺杂有少量Cd2+或/和Pb2+离子。     

Enhanced photoresponse and photocatalytic activities of graphene quantum dots sensitized Ag/TiO2 thin film

TiO₂ thin films were fabricated through hydrothermal method. Silver nanoparticles were loaded on TiO₂ thin films via photoreduction technique. Subsequently, the graphene quantum dots (GQDs) were spin‐coated on the Ag/TiO₂ nanocomposites thin films. The crystal structure, surface morphology and UV‐vis absorbance were tested by XRD, SEM and ultraviolet‐visible spectrophotometer. These results indicated that Ag nanoparticles and GQDs are anchored on the TiO₂ nanorods. Absorbance of Ag/TiO₂ and GQDs/Ag/TiO₂ nanocomposite thin films have been extended into the visible region. Visible‐light response of the samples were investigated by electrochemical workstation. The photoresponse of the sample can be enhanced by sensitization of the Ag nanoparticles and GQDs. The enhanced visible‐light response may be due to the surface plasmon resonance of silver nanoparticles and visible absorbance of GQDs. The highest photocatalytic activity has been observed in the 9‐GQDs/Ag/TiO₂ composite thin film. The efficient charge separation and transportation can be achieved by introducing the Ag nanoparticles and GQDs in the TiO₂ thin film.     

MoS2 co-catalyst sensitized 3D TiO2/CdS photoanodes with enhanced photoelectrochemical performances

Regulating morphology and constructing heterojunctions to enhance the light absorption and boost the separation of electrons and holes are common and effective means to boost the photoelectrochemical (PEC) performances of TiO₂ photoanodes. In this study, TiO₂ nanoflowers (NFs)/CdS quantum dots (QDs)/MoS₂ nanosheets (NSs) hybrids with two type II band alignments were synthesized by facile hydrothermal, successive ionic layer adsorption and reaction, and dipping methods, respectively. The effects of different amount of MoS₂ co-catalysts on CdS decorated TiO₂ photoanodes were investigated. TiO₂ NFs/CdS QDs/MoS₂ NSs hybrids showed dramatically enhanced PEC performance, especially under visible light illumination. The photocurrent density of TiO₂ NFs/CdS QDs/MoS₂-50 was more than 10 times higher than that of TiO₂ NFs/CdS QDs. This innovative work sheds light on efficiently improving the light absorption by forming heterojunctions and accelerating the electron and hole transfer via specific band engineering design.     

PAMAM树状大分子模板法合成CdSe量子点及其发光性质的研究

以聚酰胺-胺(PAMAM)树状大分子为模板合成了CdSe量子点,X-射线粉末衍射(XRD)分析表明产品与闪锌矿结构的CdSe晶体的标准粉末衍射花样的3个强峰位置相同,透射电镜(TEM)分析显示CdSe量子点包裹在树状大分子孔隙中,分散良好.实验表明以2.5 G和3.5 G PAMAM为模板合成的产品没有检测到荧光发射,而以4.5 G PAMAM树状大分子为模板制备的产品在410～465 nm范围内有较强的荧光发射,其发光波长随反应温度改变.     

CdSe纳米颗粒敏化TiO_2纳米管阵列的光催化降解及光电催化制氢

采用胶体化学法制备不同尺寸的硒化镉纳米颗粒(CdSe-NP)胶体,并利用原位吸附法将CdSe-NP与由阳极氧化法得到的TiO2纳米管阵列(TN)复合,在可见光下降解甲基橙溶液和外加偏压制氢,分别考察CdSe-NP敏化的TiO2纳米管阵列(CdSe-NP/TN)的光催化性能和光电催化性能。对比TN,CdSe-NP/TN表现出明显增强的光催化活性及更优异的光电催化性能,而过大的CdSe-NP尺寸则不利于复合材料的催化活性。表征结果表明,CdSe-NP/TN优异的性能是由于敏化CdSe-NP后吸收边红移以及光生电子和空穴复合率降低。     

High-efficiency photoelectrochemical performance of PbS nanoparticles sensitized TiO2 nanotube arrays

TiO₂ nanotube arrays sensitized by PbS nanoparticles (TiO₂ NTs/PbS) with enhanced visible-light activity were synthesized by a two-step approach including an electrochemical anodization technique followed by an in situ photodeposition approach. The structural investigations indicated that PbS nanoparticles grew uniformly on the walls of the TiO₂ NTs. The TiO₂ NTs/PbS exhibited more excellent photoelectrochemical properties than that of the TiO₂ NTs under visible-light irradiation. The enhanced photoelectrochemical activity of the TiO₂ NTs/PbS could be attributed to the improvement of visible-light absorption and charge separation derived from the coupling effect of the PbS nanoparticles and TiO₂ NTs.     

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。     

镧和铁掺杂纳米TiO_2的制备及其光催化性能

采用溶胶-凝胶法,制备了TiO2、Fe3+/TiO2、La3+/TiO2、Fe3+-La3+/TiO2光催化剂。考察了焙烧温度、焙烧时间和掺杂离子的种类和用量对催化剂用于紫外光催化降解亚甲基蓝性能的影响。制备纯TiO2、Fe3+/TiO2和La3+/TiO2的适宜焙烧温度分别为673,673和773 K,适宜焙烧时间为120min(TiO2)、180min(La3+/TiO2)。La3+/TiO2中La3+的适宜掺杂量为1.0%,Fe3+/TiO2中Fe3+的适宜掺杂量为0.04%,Fe3+-La3+/TiO2中,当La3+的掺杂量为1.0%时,Fe3+的适宜掺杂量为0.02%,相应的脱色率为99.83%,99.51%,98.73%。当掺杂量适当时,4种催化剂用于紫外光催化降解亚甲基蓝的活性次序为:La3+/TiO2>Fe3+/TiO2>Fe3+-La3+/TiO2>TiO2。根据XRD结果,由谢乐公式估算出所得光催化剂为纳米粒子。     

Enhancement of photocatalytic and photoelectrochemical properties of BiOI nanosheets and silver quantum dots co-modified TiO2 nanorod arrays

In this study, TiO₂ nanorod arrays (TNR), Ag quantum dots (QDs) sensitized with TNR TiO₂/Ag, bismuth oxyhalide (BiOI) nanosheets, and Ag QDs co-modified with TNR and TiO₂/BiOI/Ag (TBA) were prepared by a stepwise process. The morphological, structural, compositional, optical, photocatalytic (PC), and photoelectrochemical (PEC) properties of the samples were investigated. The TBA-2 sample exhibited the highest photocurrent density (281.8 μA/cm²) and photodegradation efficiency (93.3%), with values 9.7 times and 2.25 times higher than those for TNR, respectively. The improvement in sample performance can be attributed to the formation of a heterojunction between BiOI and TiO₂, thereby enhancing the absorption of visible light and improving the charge separation efficiency; Ag QDs limit interfacial electron-hole pair recombination. The experimental results show that TBA can effectively promote light-induced carrier transport and visible light absorption, while inhibiting the recombination rate of the electron-hole pairs, PEC, and PC.