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1.
The photoelectrochemical water splitting and simultaneous photoelectrocatalytic degradation of organic pollutant were achieved on TiO2 nanotube electrodes with double purposes of environmental protection and renewable energy production under illumination of simulated solar light. The TiO2 nanotube arrays (TiO2 NTs) were fabricated by a two-step anodization method. The TiO2 NTs prepared in two-step anodization process (2-step TiO2 NTs) showed much better surface smoothness and tube orderliness than TiO2 NTs prepared in one-step anodization process (1-step TiO2 NTs). In the photoelectrochemical water splitting and simultaneous photoelectrocatalytic decomposition process, the 2-step TiO2 NTs electrode showed both highest photo-conversion efficiency of 1.25% and effective photodecomposition efficiency with existing of methylene blue (MB) as sacrificial agent and as pollutant target. Those results implied that the highly ordered nanostructures provided direct pathway and uniform electric field distribution for effective charges transfer, as well as superior capabilities of light harvesting.  相似文献   

2.
报道了一种基于硫族金属复合物N4H9Cu7S4前驱体溶液制备硫化亚铜对电极的新方法. 分别制备了TiO2纳米颗粒多孔薄膜和TiO2纳米棒阵列结构的光阳极, 并在此基础上研究了基于硫化亚铜对电极的CdS/CdSe量子点敏化太阳电池的光电性能, 同时结合电化学阻抗技术考察了硫化亚铜对电极的催化性能. 结果表明: 与铂电极相比, 本方法制备的硫化亚铜电极对多硫电解质具有更高的催化活性, 所组装的CdS/CdSe量子点敏化太阳电池具有更优的光伏性能.  相似文献   

3.
A new ZnTe modified TiO2 nanotube (NT) array catalyst was prepared by pulse potential electrodeposition of ZnTe nanoparticles (NPs) onto TiO2 NT arrays, and its application for photocatalytic degradation of anthracene-9-carboxylic acid (9-AnCOOH) was investigated. The even distribution of ZnTe NPs was well-proportionately grown on the top surface of the TiO2 NT while without clogging the tube entrances. Compared with the unmodified TiO2 NT, the ZnTe modified TiO2 NT (ZnTe/TiO2 NT) showed significantly enhanced photocatalytic activity towards 9-AnCOOH under simulated solar light. After 70 min of irradiation, 9-AnCOOH was degraded with the removal ratio of 45% on the bare TiO2 NT, much lower than 80%, 90%, and 100% on the ZnTe/TiO2 NT with the ZnTe NPs prepared under the pulsed “on” potentials of −0.8, −1.0, and −2.0 V, respectively. The increased photodegradation efficiency mainly results from the improved photocurrent density as results of enhanced visible-light absorption and decreased hole-electron recombination due to the presence of narrow-band-gap p-type semiconductor ZnTe.  相似文献   

4.
Fe_2O_3/TiO_2纳米管阵列的制备及其光催化性能   总被引:2,自引:0,他引:2  
在钛基体上采用阳极氧化法制备了TiO2纳米管阵列,采用化学浴方法在TiO2纳米管阵列上修饰了Fe2O3纳米颗粒。利用扫描电镜、X射线衍射和紫外可见漫反射光谱等手段对材料进行了表征,同时测试了材料的光电化学性能及其光催化降解亚甲基蓝染料废水的性能。结果表明,Fe2O3纳米颗粒的修饰将TiO2纳米管阵列的光响应拓宽至可见光区域,提高了光电流,Fe2O3/TiO2纳米管阵列的光电流是未修饰的TiO2纳米管阵列的9倍。而在光催化反应中,亚甲基蓝最高降解率可达80%,比未修饰的TiO2纳米管阵列高出30%。  相似文献   

5.
在钛基体上采用阳极氧化法制备了TiO2纳米管阵列,采用化学浴方法在TiO2纳米管阵列上修饰了Fe2O3纳米颗粒.利用扫描电镜、X射线衍射和紫外可见漫反射光谱等手段对材料进行了表征,同时测试了材料的光电化学性能及其光催化降解亚甲基蓝染料废水的性能.结果表明,Fe2O3纳米颗粒的修饰将TiO2纳米管阵列的光响应拓宽至可见光区域,提高了光电流,Fe2O3/TiO2纳米管阵列的光电流是未修饰的TiO2纳米管阵列的9倍.而在光催化反应中,亚甲基蓝最高降解率可达80%,比未修饰的TiO2纳米管阵列高出30%.  相似文献   

6.
庄惠芳  赖跃坤  李静  孙岚  林昌健 《化学学报》2007,65(21):2363-2369
采用电化学阳极氧化法在钛表面构筑了一种结构有序、微米级的TiO2纳米管阵列膜层. 考察了制备电压、氧化时间、溶液搅拌等实验参数对TiO2纳米管阵列形貌和尺寸的影响. 应用SEM和XRD对膜层的形貌和晶型进行了分析和表征, 并通过TiO2纳米管阵列膜对甲基橙的光催化降解, 研究了TiO2纳米管阵列膜层结构与光催化活性的关系. 结果表明: 阳极电压和溶液搅拌对制备TiO2纳米管阵列的结构起到关键的作用. 控制20 V电压制备的TiO2纳米管阵列膜, 管长达2.6~3.3 μm, 经500 ℃热处理后具有最高的光催化活性, 其光催化性能明显优于一般的TiO2纳米颗粒膜.  相似文献   

7.
A C–N-doped TiO2 nanotube (NT)/carbon nanorod composite is fabricated by chemical vapor deposition (CVD). Carbon nanorods are grown from the TiO2 NTs, and partly graphitized, while TiO2 is in the mixture of anatase and rutile. The C–N doping shifts the absorption edge of TiO2 NTs to the visible light region; the formed carbon nanorods promote the charge carrier transfer from the TiO2 surface to the electrolyte. Under the simulated solar light irradiation, the C–N-doped TiO2 NTs show higher photocatalytic activity in the degradation of methyl orange (MO) than the undoped TiO2 NTs.  相似文献   

8.
TiO2–SrTiO3 heterostructure nanotube arrays have been utilized as a novel oxide substrate for CdS quantum dot sensitized solar cells (QDSCs). SrTiO3 on TiO2 surface passivates surface states of TiO2 and builds cascade-structured band alignment, which significantly reduces charge recombination at electrode surface. CdS/TiO2–SrTiO3 electrode exhibits a superior photoelectrochemical performance than CdS/TiO2 electrode with ~ 70% increase in external quantum efficiency. This study suggests that the suppression of charge recombination at electrode surface is critical to efficient solar energy conversion.  相似文献   

9.
In this work, CdS sensitized TiO2 nanotube arrays (CdS/TiO2NTs) electrode was synthesized with the CdS deposition on the highly ordered titanium dioxide nanotube arrays (TiO2NTs) by sequential chemical bath deposition method (S‐CBD). The as‐prepared CdS/TiO2NTs was characterized by field‐emission scanning electron microscopy (FE‐SEM) and X‐ray diffraction (XRD). The results indicated that the CdS nanoparticles were effectively deposited on the surface of TiO2NTs. The amperometric It curve on the CdS/TiO2NTs electrode was also presented. It was found that the photocurrent density was enhanced significantly from 0.5 to 1.85 mA/cm2 upon illumination with applied potential of 0.5 V at the central wavelength of 253.7 nm. The photoelectrocatalytic (PEC) activity of the CdS/TiO2NTs electrode was investigated by degradation of methyl orange (MO) in aqueous solution. Compared with TiO2NTs electrode, the degradation efficiencies of CdS/TiO2NTs electrode increased from 78% to 99.2% under UV light in 2 h, and from 14% to 99.2% under visible light in 3 h, which was caused by effective separation of the electrons and holes due to the effect of CdS, hence inhibiting the recombination of electron/hole pairs of TiO2NTs.  相似文献   

10.
TiO2 nanotube arrays were grown on Ti foil in mixed electrolyte by the anodizing process. TiO2 nanotube arrays were immersed in the TiCl4 solution to improve the photocurrent by enhanced charge transfer between TiO2 and dye molecules on the activity surface. Internal resistance of dye-sensitized solar cells (DSSC) was measured by impedance spectroscopy measurements. Backside illuminated DSSC with TiCl4-treated TiO2 nanotubes exhibited a conversion efficiency of 1.45% and showed improved electron transfer.  相似文献   

11.
采用荧光分析,暂态光电流响应分析,电化学交流阻抗谱(EIS)和Mott-Schottky响应分析考察了外加电位,光照时间,溶液pH等几个关键因素对光诱导约束刻蚀体系中TiO2纳米管阵列表面游离OH生成的影响.结果表明:当外加电位为1.0 V时,光电协同产生游离OH效率最高;OH的光催化生成与消耗能很快达到稳态,形成稳定的约束刻蚀剂层,有利于保持刻蚀过程中的精度;当pH为10时,TiO2纳米管光催化产生游离OH效率最高.研究结果对于调控和优化光诱导约束刻蚀平坦化铜的溶液体系,提高铜的刻蚀速度或平坦化精度有重要的指导意义.  相似文献   

12.
利用氨挥发诱导法在CdSe/TiO2纳米管阵列表面负载一层NixCo3-xO4。采用SEM、XRD、XPS、UV-Vis对样品进行表征,通过线性扫描伏安法测定光阳极的释氧电势来评价其光电水氧化活性。结果表明:表面NixCo3-xO4是尖晶石结构;相对于CdSe/TiO2纳米管阵列光阳极,NixCo3-xO4/CdSe/TiO2光阳极能将光电氧化水的过电势降低430 mV。Ni离子的引入使得NixCo3-xO4表面富含三价阳离子(Ni3+,Co3+),从而促进CdSe/TiO2光阳极光电水氧化的进行。  相似文献   

13.
应用电化学阳极氧化法在纯Ti基底上制备高度有序的TiO2纳米管阵列,考察了Ti/TiO2光阳极的光电化学响应.以苯酚溶液为目标污染物,研究Ti/TiO2电极的光电催化性能,并与光催化性能进行比较.结果表明,该电极光电催化性能优于光催化性能.施加0.6 V电压时,光电催化性能最好.电化学阻抗谱分析显示,光电催化和光催化降解过程的速控步骤均为表面反应步骤,外加偏压减小了界面电荷转移阻抗,提高了光生载流子的分离效率.  相似文献   

14.
A novel TiO2 nanotube array/CdS nanoparticle/ZnO nanorod (TiO2 NT/CdS/ZnO NR) photocatalyst was constructed which exhibited a wide‐absorption (200–535 nm) response in the UV/Vis region and was applied for the photoelectrocatalytic (PEC) degradation of dye wastewater. This was achieved by chemically assembling CdS into the TiO2 NTs and then constructing a ZnO NR layer on the TiO2 NT/CdS surface. Scanning electron microscopy (SEM) results showed that a new structure had been obtained. The TiO2 NTs looked like many “empty bottles” and the ZnO NR layer served as a big lid. Meanwhile the CdS NPs were encapsulated between them with good protection. After being sensitized by the CdS NPs, the absorption‐band edge of the obtained photocatalyst was obviously red‐shifted to the visible region, and the band gap was reduced from its original 3.20 eV to 2.32 eV. Photoelectric‐property tests indicated that the TiO2 NT/CdS/ZnO NR material maintained a very high PEC activity in both the ultraviolet (UV) and the visible region. The maximum photoelectric conversion efficiencies of TiO2 NT/CdS/ZnO NR were 31.8 and 5.98 % under UV light (365 nm) and visible light (420–800 nm), respectively. In the PEC oxidation, TiO2 NT/CdS/ZnO NR exhibited a higher removal ability for methyl orange (MO) and a high stability. The kinetic constants were 1.77×10?4 s?1 under UV light, which was almost 5.9 and 2.6 times of those on pure TiO2 NTs and TiO2 NT/ZnO NR, and 2.5×10?4 s?1 under visible light, 2.4 times those on TiO2 NT/CdS.  相似文献   

15.
In the present work, we show how TiO2 nanotube layers that are decorated with a Pt-nanoparticle coating can be fabricated and operated as a reusable glucose sensing system. A critical amount of Pt coating is essential not only to provide an effective catalyst for glucose oxidation but also to establish a sufficient conductivity along TiO2 nanotube walls to allow an efficient amperometric operation of the electrode. On such an electrode the self-cleaning photocatalytic features of TiO2 can be maintained and used to re-establish poisoned activity of the Pt particles.  相似文献   

16.
Porous Si/TiO2 nanowire photoanodes were prepared by a combination of hydrothermal synthesis and metal‐assisted chemical etching. Characterization of samples was conducted using scanning electron microscopy and X‐ray diffraction, the results showing that a porous Si/TiO2 heterojunction structure was synthesized. Diffuse reflection spectra show that the porous Si/TiO2 nanowire photoanodes have a strong absorption. Photocurrent measurement shows that the photocurrent of the porous Si/TiO2 nanowire photoanodes at 6 h is higher than that of others in the measuring region. The photoelectric catalysis (PEC) activities of porous Si/TiO2 nanowire photoanodes were evaluated in degradation experiments of methylene blue under simulated solar light irradiation, and the sample at 6 h shows the highest PEC activity. Meanwhile, the PEC activity of the porous Si/TiO2 nanowire photoanode is higher than that of the single direct photocatalysis process or electric catalysis. The mechanism of the PEC of the porous Si/TiO2 nanowire photoanodes has been explained.  相似文献   

17.
Hierarchically structured TiO2 (HST) films composed of top porous nanoparticle layer and underneath nanotube array layer are obtained by an anodization method on fluorine doped tin oxide surfaces. Compared with the TiO2 nanotube arrays photoanode on Ti substrate, the HST photoanode exhibits a higher photoelectrocatalytic activity towards the oxidation of water and organics (e.g., glucose).  相似文献   

18.
A large clearance TiO2 nanotube arrays (LTAs) has been synthesized by a not more than 12 h anodization duration and based on this a branched TiO2 nanotube arrays (BLTs) has been achieved through TiO2 nanorods branch-like grown on the LTAs. Some key factors and probable mechanisms of the fabrication processes on two novel nanoarchitectures are discussed. Exhilaratingly, it is found that the obtained LTAs has demonstrated large pore diameter and void spaces (pore diameter ∼350 nm; void spaces ∼160 nm; and tube length ∼3.5 μm), and the synthesized hierarchical BLTs, compared with conventional TiO2 nanotube arrays, has shown a much stronger dye absorption performance and an approximately double of the solar cell efficiency (in our case from 1.62% to 3.18% under simulated AM 1.5 conditions).  相似文献   

19.
Amperometric detection of nicotine (NIC) was carried out on a titanium dioxide (TiO2)/poly(3,4-ethylenedioxythiophene) (PEDOT)-modified electrode by a molecular imprinting technique. In order to improve the conductivity of the substrate, PEDOT was coated onto the sintered electrode by in situ electrochemical polymerization of the monomer. The sensing potential of the NIC-imprinted TiO2 electrode (ITO/TiO2[NIC]/PEDOT) in a phosphate-buffered saline (PBS) solution (pH 7.4) containing 0.1 M KCl was determined to be 0.88 V (vs. Ag/AgCl/saturated KCl). The linear detection range for NIC oxidation on the so-called ITO/TiO2[NIC]/PEDOT electrode was 0-5 mM, with a sensitivity and limit of detection of 31.35 μA mM−1 cm−2 and 4.9 μM, respectively. When comparing with the performance of the non-imprinted one, the sensitivity ratio was about 1.24. The sensitivity enhancement was attributed to the increase in the electroactive area of the imprinted electrode. The at-rest stability of the ITO/TiO2[NIC]/PEDOT electrode was tested over a period of 3 days. The current response remained about 85% of its initial value at the end of 2 days. The ITO/TiO2[NIC]/PEDOT electrode showed reasonably good selectivity in distinguishing NIC from its major interferent, (−)-cotinine (COT). Moreover, scanning electrochemical microscopy (SECM) was employed to elucidate the surface morphology of the imprinted and non-imprinted electrodes using Fe(CN)63−/Fe(CN)64− as a redox probe on a platinum tip. The imprinted electrode was further characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR).  相似文献   

20.
Owing to well‐defined structural parameters and enhanced electronic properties, highly ordered TiO2 nanotube arrays have been employed to substitute TiO2 nanoparticles for use in dye‐sensitized solar cells. To further improve the performance of dye‐sensitized TiO2 nanotube solar cells, efforts have been directed toward the optimization of TiO2 photoanodes, dyes, electrolytes, and counter electrodes. Herein, we highlight recent progress in rational structural and surface engineering on anodic TiO2 nanotube arrays and their effects on improving the power conversion efficiency of dye‐sensitized TiO2 nanotube solar cells.  相似文献   

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