苯封四聚苯胺/TiO2/ITO薄膜电极光致界面电荷转移

采用水解胶溶法和旋转涂膜法分别制备出TiO2纳米粒子溶胶和TiO2/ITO薄膜, 采用浸泡法制备出苯封四聚苯胺(聚苯胺)/TiO2/ITO薄膜电极. 利用表面光电压谱、光致循环伏安和光电流作用谱测定了TiO2的禁带宽度和表面态能级、聚苯胺的 HOMO-LUMO能级宽度和双极化子能级, 确定了聚苯胺/TiO2/ITO薄膜电极能带结构. 进一步分析了聚苯胺/TiO2/ITO薄膜电极的光电转换特性及光致界面电荷转移的机理.     

TiO2表面氧空位对Rup2P/TiO2/ITO薄膜电极光致电荷转移的影响

采用改性的TiCl4水解法制备出三种不同表面性质的TiO2-X(X=5,10,20,X表示加入NaOH的浓度,单位为mo·lL-1)样品.利用(1,10-邻菲咯啉)2-2-(2-吡啶基)苯咪唑钌混配配合物(Rup2P)作为敏化剂,制备出Rup2P/TiO2-5/ITO(铟锡金属氧化物)、Rup2P/TiO2-10/ITO和Rup2P/TiO2-20/ITO表面敏化薄膜电极.测试结果表明三种薄膜电极的光电转换效率Rup2P/TiO2-10/ITO最高,Rup2P/TiO2-20/ITO次之,Rup2P/TiO2-5/ITO最低.利用吸收光谱、表面光电压(SP)谱、荧光光谱和表面光电流作用谱等分析了Rup2P和三种TiO2的能带结构和表面性质;利用光致循环伏安和表面光电流作用谱研究了三种Rup2P/TiO2-X/ITO薄膜电极的光致界面电荷转移过程.结果表明,在光致界面电荷转移过程中,TiO2层表面氧空位对Rup2P/TiO2-X/ITO薄膜电极光致电荷转移产生重要影响.并进一步讨论了Rup2P/TiO2-X/ITO薄膜电极的光电流产生机理.     

Rup_2P表面敏化TiO_2基复合薄膜光致界面电荷转移

采用离子束溅射技术制备出TiO2/ITO、Zn2+掺杂的TiO2(TiO2-Zn)/ITO和TiO2/ZnO/ITO薄膜,采用表面敏化技术和旋转涂膜法,制备出(1,10-邻菲咯啉)2-2-(2-吡啶基)苯咪唑钌混配配合物(Rup2P)表面敏化的TiO2基复合薄膜Rup2P/TiO2/ITO、Rup2P/TiO2-Zn/ITO和Rup2P/TiO2/ZnO/ITO.表面光电压谱(SPS)结果发现:敏化后的TiO2基薄膜在可见区(400-600nm)产生SPS响应;TiO2基薄膜的能带结构不同,其在400-600nm和350nm处的SPS响应的峰高比不同.利用电场诱导表面光电压谱(EFISPS),测定TiO2基薄膜和表面敏化TiO2基复合薄膜各种物理参数,并确定其能带结构.分析可知,表面敏化TiO2基复合薄膜在400-600nm的SPS响应峰主要源于Rup2P分子的中心离子Ru4d能级到配体1,10-邻菲咯啉π*1和2-(2-吡啶基)苯咪唑π*2能级的跃迁;TiO2中Zn2+掺杂能级有利于Ru4d能级到配体π*1和π*2跃迁的光生电子向TiO2-Zn导带的注入;TiO2/ZnO异质结构有利于光生电子向ITO表面的转移,从而导致可见光(400-600nm)SPS响应增强以及光电转换效率的提高.     

不同导电基底对TiO2薄膜光致亲水性的影响

分别在导电铝合金片(Al)和具有阳极氧化铝层的非导电铝片(AAO/Al), 以及铟锡氧化物导电玻璃(ITO/glass)和普通非导电玻璃(glass)表面通过提拉法制备出TiO2/Al和TiO2/AAO/Al, 以及TiO2/ITO/glass和TiO2/glass两组TiO2薄膜样品, 通过测试紫外光照下水滴接触角的变化考察TiO2薄膜的光致亲水性. 结果表明, 相对于TiO2/Al2O3/Al, 基底导电的TiO2/Al表现出较好的光致亲水性能; 而相对于TiO2/glass, 基底导电的TiO2/ITO/glass表现出较差的光致亲水性能. 分析认为, Al和ITO两导电基底和TiO2薄膜间的不同电子转移方向影响TiO2薄膜的光致亲水性能, Al片提供电子给TiO2有助于提高以光生电子为主要初级活性物种的光致亲水性, 而ITO接受TiO2的光生电子, 导致光致亲水性的下降.     

聚苯胺/二氧化钛复合薄膜的制备及其气敏性能

室温条件下, 运用静电力自组装和原位化学氧化聚合相结合的方法制备了聚苯胺/纳米二氧化钛(PANI/TiO2)复合薄膜和聚苯胺(PANI)薄膜, 并通过XPS和SEM对薄膜进行了分析表征. 采用平面叉指电极式器件制备了PANI/TiO2复合薄膜和PANI薄膜气体传感器, 研究了其在常温下对有毒气体NH3和CO 的敏感性能. 结果表明, PANI/TiO2复合薄膜较PANI薄膜具有更优的灵敏度和响应恢复特性.     

纳米结构TiO2/3-甲基噻吩和2-噻吩甲酸共聚物复合膜电极光电化学性能

用光电流作用谱、光电流．电势图等光电化学方法研究了ITO／3-甲基噻吩和2-噻吩甲酸共聚物(CTCMT)膜电极和ITO／TiO2／CTCMT复合膜电极的光电转换性质．结果表明,CTCMT、膜为p型半导体,禁带宽度为2．36eV,价带位置为-5．52eV．在ITO／TiO2／CTCMT复合膜电极中存在p-n异质结,在一定条件下异质结的存在有利于光生电子-空穴对的分离,CTCMT、膜修饰ITO／TiO2电极可使光电流增强,光电流起始波长红移至600nm以上,使宽禁带半导体电极的光电转换效率得到改善。     

表面敏化TiO_2基复合薄膜的能带结构与光致电荷转移的研究

采用离子束溅射方法制备出TiO2/ITO,Zr4＋掺杂的TiO2（TiO2-Zr）/ITO和ZrO2/TiO2/ITO复合薄膜.利用表面敏化方法制备出（1,10-邻菲咯啉）2（3,4,5-三氟苯基）咪唑并[5,6-f]邻菲咯啉钌混配配合物[Rup2O]（p=1,10-邻菲咯啉,O=（3,4,5-三氟苯基）咪唑并[5,6...     

导电聚苯胺/TiO_2微/纳米球的制备及其结构表征

采用具有八面体形貌的氧化亚铜为模板,制备了聚苯胺/TiO2(PANI/TiO2)微/纳米球,TiO2纳米粒子很均匀地分散在聚苯胺中.研究了不同TiO2/苯胺(TiO2/ANI)摩尔比对PANI/TiO2复合物的结构、形貌和电学性能的影响.实验结果表明,随着TiO2/ANI摩尔比的增加,PANI/TiO2复合物的直径逐渐减小,当TiO2/ANI摩尔比为0.16时,复合物的平均直径为373nm,而当TiO2/ANI摩尔比增加到1.6时,复合物的平均直径降到80nm.PANI/TiO2复合微/纳米球的电导率随着TiO2/ANI摩尔比的增加先升高后降低,当TiO2/ANI摩尔比达到1.6时,电导率由10-4S/cm提高到100S/cm,达到最大值.产物的形貌和结构分别采用扫描电镜、透射电镜、红外吸收光谱和X-射线衍射等手段进行了表征.     

P3HT/CdS/TiO2/ZnO一维有序核壳式纳米棒阵列的构制及其在杂化太阳电池中的应用研究

采用恒电位法在铟锡氧化物导电玻璃(ITO)上制备了高度有序一维ZnO纳米棒阵列,将ZnO纳米棒阵列在TiO2溶胶中采用提拉法制备出了一维TiO2/ZnO核壳式纳米棒阵列.在一维TiO2/ZnO核壳式纳米棒阵列上电沉积CdS纳米晶得到一维CdS/TiO2/ZnO核壳式纳米棒阵列,然后在一维CdS/TiO2/ZnO核壳式纳米棒阵列上电沉积聚3-己基噻吩(P3HT)薄膜得到P3HT/CdS/TiO2/ZnO核壳式纳米结构薄膜.以该纳米结构薄膜电极为光阳极制备出新型纳米结构杂化太阳电池,研究了该类电池的光电转换性能,初步探讨了该类电池的工作机理.     

TiO2薄膜光催化还原Hg2+的研究

采用溶胶法制备出TiO2、SO42-/TiO2、CdS/TiO2薄膜光催化剂,研究了TiO2薄膜光催化还原Hg2+的最佳实验条件以及SO42-/TiO2、CdS/TiO2薄膜与TiO2薄膜、TiO2粉体与薄膜之间的光催化活性差异.结果表明:当pH=5.34时,经30 min紫外光照射,Hg2+的还原率达到最大;Hg2+初始浓度越高,光致还原量越低;光源波长越短,Hg2+的还原率越高;当甲醇添加量达到15%(体积比)时,反应30 min后,Hg2+的还原率即达100%;CdS改性薄膜的光催化活性高于未改性薄膜;CdS/TiO2薄膜的光催化活性略高于粉体.     

纳米结构TiO2/聚3-己基噻吩多孔膜电极光电性能研究

用光电流作用谱、光电流-电势图等光电化学方法研究了ITO/聚3-己基噻吩(ITO/ P3HT)膜和纳米结构TiO2/聚3-己基噻吩(TiO2/P3HT)复合膜的光电转换性质. 结果表明, P3HT膜的禁带宽度为1.89 eV, 价带位置为－5.4 eV. 在ITO/TiO2/ P3HT复合膜电极中存在p-n异质结, 在一定条件下异质结的存在有利于光生电子-空穴对的分离. P3HT修饰ITO/TiO2电极可使光电流发生明显的红移, 从而提高了宽禁带半导体的光电转换效率.     

负偏压下Ag@AgBr/Ni膜电极光电催化降解罗丹明B的性能和机理

用电化学方法制备Ag@AgBr/Ni表面等离子体薄膜电极,以扫描电子显微镜（SEM）、X射线衍射（XRD）和紫外-可见漫反射光谱（UV-Vis DRS）对薄膜的表面形貌、晶相结构、光吸收特性进行了表征,在负偏压和可见光作用下,以罗丹明B为模拟污染物对薄膜的光催化活性和稳定性进行了测定,采用电化学技术和向溶液中加入活性物种捕获剂的方法对薄膜光电催化降解机理进行了探索。结果表明：最佳工艺下制备的Ag@AgBr/Ni膜电极是由表面沉积纳米Ag的纳米晶AgBr颗粒构成的薄膜,具有显著的表面等离子共振效应。薄膜具有优异的光电催化活性和良好的催化稳定性,在最佳负偏压和可见光照射下反应12 min,薄膜光电催化罗丹明B（c=5 mg·L^-1）的降解率是多孔TiO₂（P25）/ITO纳米薄膜的10.2倍。相对于未加偏压的光催化,降解率提高了2.0倍;在保持薄膜光催化活性基本不变的前提下可循环使用5次。电极表面纳米Ag粒子的等离子体共振对于光阴极反应（价带反应）的活化作用是光电催化活性提高的重要原因。提出了负偏压下Ag@AgBr/Ni表面等离子体薄膜光电催化降解罗丹明B的反应机理。     

不同波长紫外光照下纳米TiO2薄膜的光致亲水性与循环伏安行为

通过溶胶-凝胶方法分别在ITO和玻璃表面制备了纳米TiO_2薄膜，研究了纳米 TiO_2薄膜在254及365nm的紫外光照射下的循环伏安行为和光致超亲水性。在紫外 光的照射下，TiO_2薄膜电极可表现出两个光电化学过程，纳米TiO_2薄膜的光致超 亲水性转变及两个光电化学过程的速率均取决于紫外光的波长，原因在于纳米 TiO_2薄膜对两种波长的光的吸收率和光子的能量不同。提出了光电化学过程的机 理，认为紫外光照射下纳米TiO_2薄膜的超亲水性变化与产生Ti~(3+)的过程引起的 表面微观结构变化存在的一定的内在联系。     

A spectroelectrochemical study on single-oscillator model and optical constants of sulfonated polyaniline film

The optical properties of sulfonated polyaniline (SPAN) thin film prepared by electrochemical method have been investigated. Polychromic behavior of SPAN thin film (transparent yellow-green-dark blue) was observed when the cyclic voltammograms were taken between -0.25 V and +1.90 V (vs. Ag/AgCl, sat.) during the growth of polyaniline film. In situ UV-vis spectra of the polymers-indium tin oxide (ITO) glass electrode were taken during the oxidation of the polymers at different applied potentials. The direct band gap values of SPAN thin film changed from 3.771 eV to 3.874 eV with the applied potentials. From in situ UV-vis spectra, the optical constants such as refractive index and dielectric constant of the SPAN thin film were determined. The important changes in absorption edge, refractive index and the dielectric constant were observed due to the applied potentials. The refractive index dispersion curves of the film obey the single-oscillator model and oscillator parameters changed with the applied potentials. The most significant result of the present work is in situ spectroelectrochemical method, which can be used to modify the optical band gaps and constants.     

负偏压下Ag@AgBr/Ni膜电极光电催化降解罗丹明B的性能和机理

用电化学方法制备Ag@Ag Br/Ni表面等离子体薄膜电极,以扫描电子显微镜(SEM)、X射线衍射(XRD)和紫外-可见漫反射光谱(UV-Vis DRS)对薄膜的表面形貌、晶相结构、光吸收特性进行了表征,在负偏压和可见光作用下,以罗丹明B为模拟污染物对薄膜的光催化活性和稳定性进行了测定,采用电化学技术和向溶液中加入活性物种捕获剂的方法对薄膜光电催化降解机理进行了探索。结果表明:最佳工艺下制备的Ag@Ag Br/Ni膜电极是由表面沉积纳米Ag的纳米晶Ag Br颗粒构成的薄膜,具有显著的表面等离子共振效应。薄膜具有优异的光电催化活性和良好的催化稳定性,在最佳负偏压和可见光照射下反应12 min,薄膜光电催化罗丹明B(c=5 mg·L~(-1))的降解率是多孔Ti O2(P25)/ITO纳米薄膜的10.2倍。相对于未加偏压的光催化,降解率提高了2.0倍;在保持薄膜光催化活性基本不变的前提下可循环使用5次。电极表面纳米Ag粒子的等离子体共振对于光阴极反应(导带反应)的活化作用是光电催化活性提高的重要原因。提出了负偏压下Ag@Ag Br/Ni表面等离子体薄膜光电催化降解罗丹明B的反应机理。     

Direct electrodeposition of gold nanoparticles onto indium/tin oxide film coated glass and its application for electrochemical biosensor

A novel electrochemical deposition method for growth of gold nanoparticles (GNPs) on indium tin oxide (ITO) thin film coated glass was investigated. The resulting electrode surface was characterized by SEM, UV–Vis spectroscopy and electrochemical methods. The GNPs directly attached on the electrode surface with a quasi-spherical shape and their sizes of diameters were in the range of 20–35 nm with a quite symmetric distribution. With increasing electrodeposition cycles of cyclic voltammetry, the density of GNPs on ITO electrode surface was increased. The potential utility of the GNPs modified ITO electrode was investigated. Superoxide dismutase (SOD) was successfully immobilized on GNPs modified ITO electrode and the direct electron transfer between enzyme and electrode surface realized. The enzyme electrode exhibited a rapid and high response to superoxide anion.     

Efficient charge injection from the S2 photoexcited state of special-pair mimic porphyrin assemblies anchored on a titanium-modified ITO anode

A novel surface fabrication methodology has been accomplished, aimed at efficient anodic photocurrent generation by a photoexcited porphyrin on an ITO (indium-tin oxide) electrode. The ITO electrode was submitted to a surface sol-gel process with titanium n-butoxide in order to deposit a titanium monolayer. Subsequently, porphyrins were assembled as monolayers on the titanium-treated ITO surface via phosphonate, isophthalate, and thiolate groups. Slipped-cofacial porphyrin dimers, the so-called artificial special pair at the photoreaction center, were organized through imidazolyl-to-zinc complementary coordination of imidazolylporphyrinatozinc(II) units, which were covalently immobilized by ring-closing olefin metathesis of allyl side chains. The modified surfaces were analyzed by means of X-ray photoelectron spectroscopy. Photoirradiation of the porphyrin dimer generated a large anodic photocurrent in aqueous electrolyte solution containing hydroquinone as an electron sacrificer, due to the small reorganization energy of the dimer. The use of different linker groups led to significant differences in the efficiencies of anodic photocurrent generation. The apparent flat-band potentials evaluated from the photocurrent properties at various pH values and under biased conditions imply that the band structure of the ITO electrode is modified by the anchoring species. The quantum yield for the anodic photocurrent generation by photoexcitation at the Soret band is increased to 15 %, a surprisingly high value without a redox cascade structure on the ITO electrode surface, while excitation at the Q band is not so significant. Extensive exploration of the photocurrent properties has revealed that hot injection of the photoexcited electron from the S2 level into the conduction band of the ITO electrode takes place before internal conversion to the S1* state, through the strong electronic communication of the phosphonyl anchor with the sol-gel-modified ITO surface.     

Two Photoelectrochemical Processes for TiO2 Electrode under UV Illumination

TiO2 thin film electrode was prepared by a sol-gel method on ITO substrates. Cyclic voltammetric behavior of the ITO/TiO2 electrode under ultraviolet (UV) illumination was investigated in the solution of Na2SO4.There are two photoelectrochemical processes for TiO2 electrode under UV illumination.One is a fast process,which results in the appearance of anodic photocurrent.The anodic photocurrent will appear and disappear with the light on and off.The other is a slow process,which will be responsible for the appearance of an oxidative peak. When the electrode is illuminated under UV light for a long time,a new oxidative peak can be observed.The peak current increases with the increase of UV illumination time.It is assumed that the new peak belongs to the oxidation of Ti^3 ,which formed and accumulated on the electrode surface during the UV illumination.A detailed mechanism is proposed on the base of these two photoelectrochemical processes.It is assumed that the change of hydrophilicity of TiO2 thin film may be related to the slow process while the film irradiated by UV light.     

固态光电催化器件 ITO/TiO2/ITO 的构型和机制

 采用浸渍-提拉法将 TiO₂ 薄膜负载在具有一定电极构型的氧化铟锡 (ITO) 基底上, 制备了全固态 TiO₂ 平面型器件 (ITO/TiO₂/ITO). 采用扫描电镜对器件的表面形貌和膜厚进行了表征. 以紫外光下器件光电协同催化降解罗丹明 B(RhB) 为模型反应, 考察了器件的构型和空穴捕获剂 (乙醇) 对其光电催化性能的影响. 结果表明, 初始浓度为 10 mg/L 的 RhB 在 1.5 V 偏压和 NaCl (1.5 mol/L) 为电解质的条件下, 光照 60 min 脱色率达到 83%; 阳极面积较大的器件光电催化性能较好, 刻蚀宽度为 2 mm 时光电催化活性最高; 空穴与 TiO₂表面吸附的 H₂O 氧化生成的羟基自由基对液相光电催化降解 RhB 起着重要作用.     

TiO2 photoanodes prepared by cathodic electrophoretic deposition in 2-propanol: effect of the electric field and deposition time

This paper evaluates the influence of electric field and deposition time applied on cathodic electrophoretic formation of TiO₂ films in organic medium (2-propanol). The film morphology was tracked by measuring the deposited mass and film thickness. The variation in film porosity was correlated with the apparition of surface states distribution in the cyclic voltammetric characterization in the dark, due to grain boundaries defects generated in the contact of the TiO₂ particles. The open-circuit voltage decay curves showed that there is no formation of deep energy states inside the band gap of the TiO₂. The photopotential of the films increased until a critical thickness but the photocurrents showed to be dependent on operational variables, due to the fact that anodic polarization in thin films increases the electric field generated by the illumination at the ITO/TiO₂ interface, favoring the transport of the photogenerated electrons to the rear contact.