铜电极在含苯并三唑的硼砂-硼酸缓冲溶液中的光电化学行为研究

用光电化学方法研究了铜电极在含苯并三唑(BTA)的硼砂—硼酸缓冲溶液中的光电化学行为.BTA能使铜电极的光响应由p-型转变为n-型.产生光响应的原因是铜电极表面的Cu_2O膜, 当BTA存在时由于BTA的作用致使电极表面Cu_2O膜中共存着P-型和n-型区域,电位正移和频率增加导致电极显示n-型光响应.     

铅电极在硫酸溶液中的光电化学行为

研究了铅电极在阳极氧化过程中光响应的产生机制。结果表明，Ｐｂ电极在光照氧化时存光活化过程，且光经过程须在电位高于０Ｖ时才能发生。采用现场测量光电压技术研究了Ｐｂ电极在硫酸溶液中的恒电流极化过程。     

n-CdSe/Fe(CN)64-/3-光阳极上的光氧化竞争反应及用L-B技术修饰电极的影响

用旋转环盘电极研究了还原剂K₄Fe(CN)₆与n-CdSe光阳极上的竞争空穴的氧化反应,证明还原剂捕获光生空穴的途径为直接自价带俘获空穴。又利用L-B技术在n-CdSe电极表面修饰硬脂酸二茂铁酯,结果表明还原剂俘获光生空穴的能力增强,电极的稳定系数提高。     

双染料复合敏化SnO2纳米多孔膜光电极的研究

光电化学;光电转换;双染料复合敏化SnO2纳米多孔膜光电极的研究     

铜电极光电响应p型转变为n型的机理探讨

用动电位扫描和η（量子效率）～hv关系研究了钢电极在含或不含氯离子的硼砂－硼酸缓冲溶液中的电化学和光电化学行为.当溶液中不含氧离子时，铜电极呈p型光响应；相当量的氯离子存在时，光响应从p型转变为n型. 研究表明p→n的转型不是由于电极表面生成了化合物CuCl，而应归因于氯离子对Cu2O膜的掺杂.     

铜电极在含苯并三唑的硼砂-硼酸缓冲溶液中的光电化学行为研究

用光电化学方法研究了铜电极在含苯并三唑(BTA)的硼砂-硼酸缓冲溶液中的光电化学行为。BTA能使铜电极的光响应由p-型转变为n-型。产生光响应的原因是铜电极表面的Cu2O膜。当BTA存在时由于BTA的作用致使电极表面Cu2O膜中共存着p-型和n-型区域, 电位正移和频率增加导致电极显示n-型光响应。     

3,3′,5,5′-四甲基联苯胺在铂网栅光透电极上的薄层光谱电化学

3; 3′; 5; 5′-四甲基联苯胺在铂网栅光透电极上的薄层光谱电化学;薄层光谱电化学; 四甲基联苯胺; 电氧化; 铂网栅光透电极     

NiOOH/ZnO复合光阳极制备与性能研究

以NiOOH为助催化剂对ZnO进行改性,采用电化学沉积方法制备了纳米阵列结构的NiOOH/ZnO复合光电极。运用X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、傅立叶红外光谱仪(FT-IR)和紫外可见光谱(UV-Vis)等测试手段对样品进行表征,并用电化学方法研究电极材料的光电化学性能。结果表明,制备的复合电极中NiOOH在ZnO表面分布均匀,颗粒大小约为50 nm,该复合电极在紫外和可见光区均表现出优良的光学吸收性能;电化学研究表明,该复合电极电阻率小,在模拟太阳光条件下其光电化学响应性能比ZnO明显增强,且对甲醇有良好的光电催化性质。NiOOH/ZnO复合电极展现出的这些优良光电化学性能,预示其在光电化学领域将会有良好地应用前景。     

CuInSe2/氰桥混配物复合修饰光电极的制备及其光电性质

利用电沉积法在氰桥混配物预修饰的玻璃碳电极上再沉积CuInSe2半导体材料,制备了一种复合型修饰光电极(Eu-Fe-Mo/CuInSe2)。以含Cu2+、In3+、SeO23-及柠檬酸钠的酸性水溶液为电镀液,通过优化寻找到电镀液中最佳的Cu∶In∶Se料液比例,用恒电位电沉积法可以制备出具有良好光电效应的复合型修饰光电极。用SEM、EDS技术对复合修饰光电极的表面形貌及其修饰材料的元素组成进行了表征;以60 W的普通日光型白炽灯为光源,采用开路电压和计时安培法研究了该复合修饰光电极的光电性质。测得该光电极的响应光电压大于30 mV,响应光电流密度大于8.9×10-6A/cm2。实验结果表明,该复合修饰光电极呈现典型p型半导体的光电性质。     

硫化镉修饰电极的光电化学行为

对半导体电极表面进行修饰,使它能吸收与太阳.光谱相匹配波长范围的光和具有良好电化学活性是光电化学研究领域中的一个课题.     

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.     

Rh-doped SrTiO3 photocatalyst electrode showing cathodic photocurrent for water splitting under visible-light irradiation

A Rh-doped SrTiO(3) (SrTiO(3):Rh) photocatalyst electrode that was readily prepared by pasting SrTiO(3):Rh powder onto a transparent indium tin oxide electrode gave a cathodic photocurrent under visible-light irradiation (λ > 420 nm), indicating that the SrTiO(3):Rh photocatalyst electrode possessed p-type semiconductor character. The cathodic photocurrent increased with an increase in the amount of doped Rh up to 7 atom %. The incident-photon-to-current efficiency at 420 nm was 0.18% under an applied potential of -0.7 V vs Ag/AgCl for the SrTiO(3):Rh(7 atom %) photocatalyst electrode. The photocurrent was confirmed to be due to water splitting by analyzing the evolved H(2) and O(2). The water splitting proceeded with the application of an external bias smaller than 1.23 V versus a Pt counter electrode under visible-light irradiation and also using a solar simulator, suggesting that solar energy conversion should be possible with the present photoelectrochemical water splitting.     

热对银电极阳极膜光电流测定的影响

利用光电流 ,光热信息和热电流方法研究了热对Ag在 1mol/LNaOH溶液中表面阳极膜光电流的影响 .所用光源为 4 88nm和 5 32nm的激光 .结果表明Ag2 O层具有半导体光电流特性 ,在Ag ,Ag2 O和AgO的转变过程中 ,光照下电极表面的温升不同 .对照循环伏安曲线 ,及光电流和热电流曲线 ,可以证明在电位朝负方向扫描过程中于 0 .37V出现的阳极光电流峰和 0 .1V出现的阴极光电流峰主要是由光照下温度升高引起的热电流所造成的 .光电流和热电流随着光强度的增强而线性增强     

Enhanced Photoelectrochemical Property of Zn Loaded TiO2 Nanotube Arrays Electrode

TiO₂ nanotube arrays (TNTs) electrode loaded with Zn nanoparticles was prepared by anodization and the size of Zn nanoparticle loaded on TNTs electrode was controlled bychronoamperometry deposition time. Results of SEM and XRD analysis show that Zn nanoparticles had a diameter of about 15-25 nm when the deposition time was 3-5 s. The UV-Vis diffuse reflectance spectra show the Zn loaded harvest light with 480-780 nm more effectively than the unloaded sample. The photocurrent response of Zn loaded TNTs electrodes were studied, the results showed that TNTs electrodes loaded with Zn nanoparti-cles has 50% increased photocurrent response under high-pressure mercury lamp irradiation compared with unloaded TNTs electrode.     

TiNi合金表面原位热氧化膜的结构与光电性能的研究

采用AFM、XRD和EDS等手段,对TiNi合金在空气中、400—800℃下形成的氧化膜组织结构进行了分析,并对TiNi合金表面原位热氧化膜的光电性能进行了研究.结果表明,TiNi合金在空气中氧化原位形成的氧化膜的结构主要为金红石型二氧化钛,不同温度下生长的氧化膜存在择优取向;随着氧化温度的升高,所制备的TiO2/TiNi电极的稳态光电流和开路光电压随氧化温度的升高先增大后减小,在700℃所制备的TiO2/TiNi电极的稳态光电流最大.     

Photoelectrocatalytic disinfection of E. coli suspensions by iron doped TiO2

Photoelectrocatalytic disinfection of E. coli by an iron doped TiO(2) sol-gel electrode is shown to be more efficient than disinfection by the corresponding undoped electrode. Thus, the improvements in photocatalytic efficiency associated with selective doping have been combined with the electric field enhancement associated with the application of a small positive potential to a UV irradiated titanium dioxide electrode. The optimum disinfection rate corresponds to the replacement of approximately 0.1% of the Ti atoms by Fe. The enhanced disinfection associated with iron doping is surprising because iron doping decreases the photocurrent, and photocurrent is generally taken to be a good indicator of photoelectrocatalytic efficiency. As the level of iron is increased, the character of the current-voltage curve changes and the enhancement of photocurrent associated with methanol addition decreases. This suggests that iron reduces the surface recombination which in the absence of iron is reduced by methanol. Therefore the enhanced photocatalysis is interpreted as due to iron reducing surface recombination, by trapping electrons. It is proposed that at low iron levels the photo-generated electrons are trapped at surface Fe(III) centres and that consequently, because the electron-hole recombination rate is reduced, the number of holes available for hydroxyl radical formation is increased. It is also proposed that at higher iron levels, the disinfection rate falls because electron hole recombination at iron centres in the lattice reduces the number of holes which reach the surface. Our conclusion that the optimum electrode performance is a balance between surface and bulk effects is consistent with the proposal, of earlier authors for photocatalytic reactions, that the optimum dopant level depends on the TiO(2).     

十八硫醇自组装膜对TiO2光电氧化甲醇的敏化作用

纳米电极;甲醇光电氧化;十八硫醇自组装膜对TiO2光电氧化甲醇的敏化作用     

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.     

Artificial photosynthesis by using chloroplasts from spinach adsorbed on a nanocrystalline TiO2 electrode for photovoltaic conversion

Photovoltaic conversion has been achieved by use of chloroplasts (photosynthetic organs) from spinach adsorbed on a nanocrystalline TiO₂ film on an indium tin oxide (ITO) glass electrode (chloroplast/TiO₂ electrode). The shape of the absorption spectrum of the chloroplast/TiO₂ electrode is almost the same that of a dispersion of the chloroplasts. Absorption maxima of the chloroplast/TiO₂ electrode observed at 430, 475, and 670 nm were attributed to carotenoid and chlorophyll molecules, suggesting that chloroplasts have been adsorbed by the nanocrystalline TiO₂ film on the ITO electrode. The photocurrent responses of chloroplast/TiO₂ electrodes were measured by using a solution of 0.1 M tetrabutylammonium hexafluorophosphate in acetonitrile as redox electrolyte in the presence or absence of water and 100 mW cm^?2 irradiation. The photocurrent of the chloroplast/TiO₂ electrode was increased by adding water to the redox electrolyte. The photocurrent responses of chloroplast/TiO₂ electrodes irradiated with monochromatic light (680 nm, the absorption band of photosystem II complexed with evolved oxygen) were measured by use of a solution of 0.1 M tetrabutylammonium hexafluorophosphate in acetonitrile as redox electrolyte in the presence or absence of water. A chloroplast/TiO₂ electrode photocurrent was observed only when the redox electrolyte containing water was used, indicating that the oxygen evolved from water by photosystem II in chloroplasts adsorbed by a nanocrystalline TiO₂ film on an ITO electrode irradiated at 680 nm is reduced to water by the catalytic activity of the platinum electrode. The maximum incident photon-to-current conversion efficiency (IPCE) was 0.8 % on irradiation at 670 nm.