Highly ordered combined structure of anodic TiO2 nanotubes and TiO2 nanoparticles prepared by a novel route for dye-sensitized solar cells

Combined structure of anodic TiO₂ nanotubes and TiO₂ nanoparticles (TiNTs-TiNPs) has been synthesized by a facile combination of hydrothermal and chemical vapor deposition methods. Ordered TiO₂ nanotubes with smooth walls were fabricated by two step anodization method in ethylene glycol containing NH₄F at 50 V. This nanotubular array after annealing at 450 °C was subjected to the hydrothermally produced gaseous environment in an autoclave with diluted TiCl₄ solution at its bottom. Vapors of TiCl₄ were allowed to react chemically with water vapors for predefined time durations at 180 °C that resulted in the deposition of TiO₂ nanoparticles on tubes’ surface and side walls. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed that for one hour reaction duration, nanoparticles were evenly coated on the walls of nanotubes, whereas, longer durations tend to deteriorate the tubular structure. Consequently, the ordered TiNTs-TiNPs array produced after one hour coating has shown better performance for dye-sensitized solar cell DSSC) in back illumination mode with 130% increase in efficiency as compared to the device based on bare TiO₂ nanotubes. The same photoanode has higher reflective properties with higher scattering ability. The solar cell based on this photoanode exhibits higher external quantum efficiency and effective charge transport properties. This study shows that porous ordered 1D structures based on TiO₂ are of crucial importance for the high performance of DSSCs.     

含氯离子电解液中二氧化钛纳米管的阳极氧化形成机理及应用

采用电化学阳极氧化的方法,以氯化铵(NH₄Cl)水溶液为电解液,在纯钛表面制备了二氧化钛(TiO₂)纳米管。考察了制备电压、氧化时间、Cl^-浓度和钛基体的退火处理对阳极氧化过程的影响规律,探讨了在含氯离子电解液中纳米管的形成机理,并基于上述含氯离子电解液中纳米管形成机制,通过两步阳极氧化法得到无支撑纳米管薄膜。     

Enhanced photovoltaic characterization and charge transport of TIO2 nanoparticles/nanotubes composite photoanode based on indigo carmine dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) have established themselves as an alternative to conventional solar cells owing to their remarkably high power conversion efficiency, longtime stability and low-cost production. DSSCs composed of a dyed oxide semiconductor photoanode, a redox electrolyte and a counter electrode. In these devices, conversion efficiency is achieved by ultra-fast injection of an electron from a photo excited dye into the conduction band of metal oxide followed by subsequent dye regeneration and holes transportation to the counter electrode. The energy conversion efficiency of DSSC is to be dependent on the morphology and structure of the dye adsorbed metal oxide photoanode. Worldwide considerable efforts of DSSCs have been invested in morphology control of photoanode film, synthesis of stable optical sensitizers and improved ionic conductivity electrolytes. In the present investigation, a new composite nano structured photoanodes were prepared using TiO₂ nano tubes (TNTs) with TiO₂ nano particles (TNPs). TNPs were synthesized by sol–gel method and TNTs were prepared through an alkali hydrothermal transformation. Working photoanodes were prepared using five pastes of TNTs concentrations of 0, 10, 50, 90, and 100 % with TNPs. The DSSCs were fabricated using Indigo carmine dye as photo sensitizer and PMII (1-propyl-3-methylimmidazolium iodide) ionic liquid as electrolyte. The counter electrode was prepared using Copper sulfide. The structure and morphology of TNPs and TNTs were characterized by X-ray diffraction and electron microscopes (TEM and SEM). The photocurrent efficiency is measured using a solar simulator (100 mW/cm²). The prepared composite TNTs/TNPs photoanode could significantly improve the efficiency of dye-sensitized solar cells owing to its synergic effects, i.e. effective dye adsorption mainly originated from TiO₂ nanoparticles and rapid electron transport in one-dimensional TiO₂ nanotubes. The results of the present investigation suggested that the DSSC based on 10 % TNTs/TNPs showed better photovoltaic performance than cell made pure TiO₂ nanoparticles. The highest energy-conversion efficiency of 2.80 % is achieved by composite TNTs (10 %)/TNPs film, which is 68 % higher than that pure TNPs film and far larger than that formed by bare TNTs film (94 %). The charge transport and charge recombination behaviors of DSSCs were investigated by electrochemical impedance spectra and the results showed that composite TNTs/TNPs film-based cell possessed the lowest transfer resistances and the longest electron lifetime. Hence, it could be concluded that the composite TNTs/TNPs photoanodes facilitate the charge transport and enhancing the efficiencies of DSSCs.     

Blue TiO2 nanotube arrays as semimetallic materials with enhanced photoelectrochemical activity towards water splitting

In the past years there has been a great interest in self-doped TiO₂ nanotubes (blue TiO₂ nanotubes) compared to undoped ones owing to their high carrier density and conductivity. In this study, blue TiO₂ nanotubes are investigated as photoanode materials for photoelectrochemical water splitting. Blue TiO₂ nanotubes were fabricated with enhanced photoresponse behavior through electrochemical cathodic polarization on undoped and annealed TiO₂ nanotubes. The annealing temperature of undoped TiO₂ nanotubes was tuned before cathodic polarization, revealing that annealing at 500 °C improved the photoresponse of the nanotubes significantly. Further optimization of the blue TiO₂ nanotubes was achieved by adjusting the cathodic polarization parameters. Blue TiO₂ nanotubes obtained at the potential of –1.4 V (vs. SCE) with a duration of 10 min exhibited twice more photocurrent response (0.39 mA cm^-2) compared to the undoped TiO₂ nanotube arrays (0.19 mA cm^-2). Oxygen vacancies formed through the cathodic polarization decreased charge recombination and enhanced charge transfer rate; therefore, a high photoelectrochemical activity under visible light irradiation could be achieved.     

The Synthesis and Photocatalytic Properties of TiO2 Nanotube Array by Starch‐Modified Anodic Oxidation

In this study, the characterization and photocatalytic activity of TiO₂ nanotube arrays prepared by anodization process with starch addition were investigated in detail. The results suggested that the optimum mass fraction of starch added in anodization process was 0.1%, with which TiO₂ nanotube arrays owning good tubular structure were synthesized. The tube length and average inner diameter of nanotubes were approximately 4 μm and 30 nm, respectively. Through the characterization of TiO₂ nanotube arrays by energy dispersive spectrometer, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier Transform Infrared (FTIR) spectroscopy, it was found that the as‐prepared nanotubes possessed well uniformed and higher photodegradation responsive than the pure TiO₂. Moreover, it was expected that the as‐prepared nanotubes exhibited good photocatalytic activity for the degradation of RhB under UV‐light irradiation, which could be ascribed to their good morphology, enhanced UV‐light absorption property and electron transmission ability during the photocatalytic reaction. In addition, the nanotubes were not significantly regenerated during the cycling runs experiment. Overall, this study could provide a principle method to synthesize TiO₂ nanotube arrays with enhanced photocatalytic activity by anodization process with starch addition for environmental purification.     

The fabrication of TiO<Subscript>2</Subscript> nanoparticle/ZnO nanowire arrays bi-filmed photoanode and their effect on dye-sensitized solar cells

Porous TiO₂ nanoparticles coated on ZnO nanowire arrays (TiO₂ NP/ZnO NW) as photoanode for dye-sensitized solar cell (DSSC) has been fabricated and investigated to improve the power conversion efficiency. The TiO₂ NP/ZnO NW photoanode consists of single crystalline ZnO NWs synthesized via hydrothermal method and porous TiO₂ NP film covered on the surface of ZnO NW arrays by screen printing technique. The effect of TiO₂ NPs thickness of the bi-filmed photoanode on the cell performance has been investigated, and TiO₂ NP/ZnO NW DSSC with NP thickness of ~5 μm exhibits the best efficiency of 4.68%, higher than 1.16% of ZnO NW DSSC and 3.18% of TiO₂ NPs DSSC, prepared and tested under identical conditions. The efficiency increase is attributed to the enlarged photocurrent, due to the greatly enhanced surface area for dye absorption and light harvesting efficiency resulted from TiO₂ NPs, and improved open-circuit voltage, due to reduced electron recombination by providing direct conduction pathway along ZnO NWs.     

Improvement the wastewater purification by TiO2 nanotube arrays: The effect of etching-step on the photo-generated charge carriers and photocatalytic activity of anodic TiO2 nanotubes

The current study demonstrates how the etching step in anodization process effects on the photocatalytic activity of TiO₂ nanotubes. In this regard, the TiO₂ nanotubes were made by one-step and two-step anodization process on two different substrates Ti and etched-Ti foils, respectively. The results revealed that two-step anodization process is a beneficial way to prepare highly well-organized structure and regular surface. The two-step anodization by an enhancement in the fluoride ions diffusion led to a decrease in nanotubes' porosity and an increment in the nanotubes’ surface area, a factor of roughness, and the ratio of length to diameter, respectively. As a consequence of the improvement in geometrical properties, the two-step TiO₂ nanotubes led to the intensification of photocurrent density (from 0.383 to 0.677 mA cm⁻²⁾ and photoconversion efficiency (from 0.18% to 0.29%) in comparison with the one-step nanotubes, respectively. Further, a synergetic impact of the photoelectrochemical measurement and photocatalytic process was observed. The degradation efficiencies of 2,4-dichlorophenol by two-step nanotubes increased from 47 to 55% under visible light, and from 58 to72% under UV irradiation, which it was attributed to more light harvesting, more photo-generated electrons, higher separation efficiency and improvement in geometrical properties. Furthermore, the kinetic study showed that the reactions follow first-order kinetics and the reaction rate constants by two-step nanotubes are 1.25 and 1.44 times as great as those of one-step nanotubes under visible and UV irradiation, respectively. Moreover, the reusability tests showed that 2-step TiO₂ nanotubes has good stability and is active even up to the Fifth run.     

A facile one-step preparation of hierarchically-structured TiO2 nanotube array photoanodes with enhanced photocatalytic activity

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).     

Electrochromic properties of anodically grown mixed V2O5–TiO2 nanotubes

Mixed V₂O₅–TiO₂ nanotube arrays were fabricated by self-organizing anodization of different Ti–V alloys. The mixed oxide nanotubes show switchable V-oxidation states and strong cathodic coloration. Already a low V content of ≈ 0.2 at.% significantly increases the electrochromic switching properties. Using a sample with 3 at.% V, very high electrochromic contrast can be established and a significantly lower switching onset voltage than for pure TiO₂ nanotubes is observed. At high V contents, although charge storage is increased, the improvement of contrast is diminished due to the strong background color of the sample.     

Hierarchical TiO2 nanosheet‐assembled nanotubes with dual electron sink functional sites for efficient photocatalytic degradation of rhodamine B

A novel Pt–TiO₂/Ag nanotube photocatalyst has been synthesized successfully via a facile method. TiO₂ nanotubes are assembled with numerous ultrathin TiO₂ nanosheets and show a highly open structure. The gaps between adjacent TiO₂ nanosheets can serve as channels for the access of reactants, accelerating the mass transfer process. During the fabrication process of the Pt–TiO₂/Ag nanotube photocatalyst, high‐quality Pt–SiO₂ nanotubes are synthesized first with the structure‐directing effect of polyvinylpyrrolidone. Then a TiO₂ layer is coated on the outside surface of the silica nanotubes. The introduced titanium species can be converted into TiO₂ nanosheet structure during the subsequent hydrothermal treatment, gradually constructing nanosheet‐assembled nanotubes. Lastly, after the introduction of another electron sink function site of Ag through UV irradiation, the Pt–TiO₂/Ag nanotube photocatalyst with dual electron sink functional sites is obtained. The specially doped Pt and Ag NPs can simultaneously inhibit the recombination process of photogenerated charge carriers and increase light utilization efficiency. Therefore, the as‐synthesized Pt–TiO₂/Ag nanotube catalyst exhibits a high photocatalytic degradation performance for rhodamine B of 0.2 min^?1, which is about 3.2 and 5.3 times as high as that of Pt–TiO₂ and TiO₂ nanotubes because of the enhanced charge carrier separation efficiency. Furthermore, in the unique nanoarchitecture, the nanotubes are assembled with numerous ultrathin TiO₂ nanosheets, which can absorb abundant active species and dye molecules for photocatalytic reaction. On the basis of experimental results, a possible rhodamine B degradation mechanism is proposed to explain the excellent photocatalytic efficiency of the Pt–TiO₂/Ag nanotube photocatalyst.     

Extensive enhancement in power conversion efficiency of dye-sensitized solar cell by using Al-doped TiO<Subscript>2</Subscript> photoanode

In this work, we have prepared Al-doped TiO₂ nanoparticles via a hydrothermal method and used it for making photoanode in dye-sensitized solar cell (DSSC). Material characterizations were done using XRD, AFM, SEM, TEM and EDAX. XPS results reveal that Al is introduced successfully into the structure of TiO₂ creating new impurity energy levels in the forbidden gap. This resulted in tuning of the conduction band of TiO₂ and reduced charge recombination which led to better current conversion efficiency of DSSC. Greater dye loading and enhanced surface area was obtained for Al-doped TiO₂ compared to un-doped TiO₂. I-V analysis, EIS and Bode plots are employed to evaluate photovoltaic performance. The short-circuit current density (J _sc) and efficiency (η) of cell employing Al-doped TiO₂ photoanode were extensively enhanced compared to the cell using un-doped TiO₂. The optical band gap (E _g) for Al-doped and un-doped TiO₂ was obtained as 2.8 and 3.2 eV, respectively. J _sc and η were 13.39 mAcm^?2 and 4.27%, respectively, under illumination of 100 mWcm^?2 light intensity when thin films of 1% Al-doped TiO₂ was employed as photoanode in DSSC using N719 as the sensitizer dye. With the use of un-doped TiO₂ as photoanode under similar conditions, J _sc 5.12 mAcm^?2 and η 1.06% only could be obtained. The maximum IPCE% obtained with Al-doped TiO₂ and un-doped TiO₂ was 67 and 38% respectively at the characteristic wavelength of dye (λ _max = 540 nm). The EIS analyses revealed resistive and capacitive elements that provided an insight into various interfacial processes in terms of the charge transport. It was observed that Al-doping reduced the interfacial resistance leading to better charge transport which has improved both photocurrent density and conversion efficiency. Higher electron mobility and fast diffusion resulting in greater charge collection efficiency was obtained for Al-doped TiO₂ compared to the un-doped TiO₂. Using the Mott–Schottky plot, the donor density was calculated for un-doped and Al-doped TiO₂. The work demonstrated that the Al-doped TiO₂ is potential photoanode material for low-cost and high-efficiency DSSC.     

Elementary Photoelectronic Processes at a Porphyrin Dye/Single‐Walled TiO2 Nanotube Hetero‐interface in Dye‐Sensitized Solar Cells: A First‐Principles Study

A unique one‐dimensional (1D) sandwich single‐walled TiO₂ nanotube (STNT) is proposed as a photoanode nanomaterial with perfect morphology and large specific surface area. We have thoroughly examined the elementary photoelectronic processes occurring at the porphyrin dye/STNT hetero‐interface in dye‐sensitized solar cells (DSSCs) by theoretical simulation. It is desirable to investigate the interfacial photoelectronic processes to elucidate the electron transfer and transport mechanism in 1D STNT‐based DSSCs. We have found that the photoexcitation and interfacial charge separation mechanism can be described as follows. A ground‐state electron of the dye molecule (localized around the electron donor) is first promoted to the excited state (distributed electron donor), and then undergoes ultrafast injection into the conduction band of the STNT, leaving a hole around the oxidized dye. Significantly, the injected electron in the conduction band is transported along the STNT by means of Ti 3d orbitals, offering a unidirectional electron pathway toward the electrode for massive collection without the observation of trap states. Our study not only provides theoretical guidelines for the modification of TiO₂ nanotubes as a photoanode material, but also opens a new perspective for the development of a novel class of TiO₂ nanotubes with high power‐generation efficiency.     

Photoelectrochemical water splitting and simultaneous photoelectrocatalytic degradation of organic pollutant on highly smooth and ordered TiO2 nanotube arrays

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.     

Preparation and characterization of Zr doped TiO2 nanotube arrays on the titanium sheet and their enhanced photocatalytic activity

This paper described a new method for the preparation of Zr doped TiO₂ nanotube arrays by electrochemical method. TiO₂ nanotube arrays were prepared by anodization with titanium anode and platinum cathode. Afterwards, the formed TiO₂ nanotube arrays and Pt were used as cathode and anode, respectively, for preparation of Zr/TiO₂ nanotube arrays in the electrolyte of 0.1 M Zr(NO₃)₄ with different voltage and post-calcination process. The nanotube arrays were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and UV-Vis diffusion reflection spectra (DRS). The photocatalytic activities of these nanotubes were investigated with Rhodamine B as the model pollutant and the results demonstrated that the photocatalytic efficiency of Zr doped TiO₂ nanotubes was much better than that of TiO₂ nanotubes under UV irradiation. Zr/TiO₂ nanotube arrays doped at 7 V and calcined at 600 °C (denoted as TiO₂-7 V-600) achieved the best photocatalytic efficiency and the most optimal doping ratio was 0.047 (Zr/Ti). TiO₂-7 V-600 could be reused for more than 20 times and maintained good photocatalytic activities.     

TiO2一维纳米材料及其纳米结构的合成

本文对合成TiO₂一维纳米材料及其有序纳米阵列的阳极氧化法、模板法以及水热法进行了全面而系统的评述，着重介绍了它们的最新研究进展。阳极氧化法能制备牢固负载于基体上的TiO₂纳米管阵列，这有助于构筑TiO₂纳米结构及其在纳米器件上的应用；与多种制备技术如溶胶－凝胶工艺、电化学沉积以及原子层沉积等相结合，模板法可以合成出多种形貌的TiO₂纳米材料如纳米管、纳米线和纳米棒，并可以通过改变所用模板的微观尺寸来调控TiO₂一维纳米材料及其有序阵列的微结构参数；水热合成法可以制备出直径小且比表面积大的TiO2纳米管粉末。但从目前看来，该法还不能制备出牢固负载于基体上的有序纳米阵列。文章最后指出了TiO₂一维纳米材料及其有序纳米阵列合成中存在的问题及今后发展方向。     

Controllable synthesis of well-ordered TiO2 nanotubes in a mixed organic electrolyte for high-efficiency photocatalysis

Well-ordered TiO 2 nanotube arrays (TNAs) were fabricated by electrochemical anodization in a mixed organic electrolyte consisting of ethylene glycol and glycerol. The morphology, structure, crystalline phase, and photocatalytic properties of TNAs were characterized by using TEM, SEM, XRD and photodegradation of methylene blue. It was found that the morphology and structure of TNAs could be significantly influenced by the anodization time and applied voltage. The obtained tube length was found to be proportional to anodization time, and the calculated growth rate of nanotubes was 0.6 m/h. The microstructure analysis demonstrated that the diameter and thickness of the nanotubes increased with the increase of anodization voltage. The growth mechanism of TNAs was also proposed according to the observed relationship between current density and time during anodization. As expected, the obtained TNAs showed a higher photocatalytic activity than the commercial TiO 2 P25 nanoparticles.     

A photoelectrochemical immunosensor based on Au-doped TiO2 nanotube arrays for the detection of α-synuclein

α‐Synuclein (α‐SYN) is a very important neuronal protein that is associated with Parkinson’s disease. In this paper, we utilized Au‐doped TiO₂ nanotube arrays to design a photoelectrochemical immunosensor for the detection of α‐SYN. The highly ordered TiO₂ nanotubes were fabricated by using an electrochemical anodization technique on pure Ti foil. After that, a photoelectrochemical deposition method was exploited to modify the resulting nanotubes with Au nanoparticles, which have been demonstrated to facilitate the improvement of photocurrent responses. Moreover, the Au‐doped TiO₂ nanotubes formed effective antibody immobilization arrays and immobilized primary antibodies (Ab₁) with high stability and bioactivity to bind target α‐SYN. The enhanced sensitivity was obtained by using {Ab₂‐Au‐GOx} bioconjugates, which featured secondary antibody (Ab₂) and glucose oxidase (GOx) labels linked to Au nanoparticles for signal amplification. The GOx enzyme immobilized on the prepared immunosensor could catalyze glucose in the detection solution to produce H₂O₂, which acted as a sacrificial electron donor to scavenge the photogenerated holes in the valence band of TiO₂ nanotubes upon irradiation of the other side of the Ti foil and led to a prompt photocurrent. The photocurrents were proportional to the α‐SYN concentrations, and the linear range of the developed immunosensor was from 50 pg mL^?1 to 100 ng mL^?1 with a detection limit of 34 pg mL^?1. The proposed method showed high sensitivity, stability, reproducibility, and could become a promising technique for protein detection.     

Photocatalytic fuel cell for simultaneous antibiotic wastewater treatment and electricity production by anatase TiO2 nanoparticles anchored on Ni foam

Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems. However, the efficient photodegradation of organic dyes and antibiotic drugs, such as ciprofloxacin (CIP) and methylene blue (MB), remains challenging. Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system, TiO₂-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach. The as-fabricated photoanode demonstrated abundant active sites, enhanced light harvesting capacity and photogenerated charge carrier separation. At a CIP-HCl concentration of 10 mg/L and pH value of about 7, 85% of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp. TiO₂-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V, short circuit current density and maximum power density of 2.4 mA/cm², 0.357 mW/cm², respectively. This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.     

Enhancing the Performance of Dye‐Sensitized Solar Cells with a Gold‐Nanoflowers Box

To improve the electron collection, electron lifetime, and light‐harvesting efficiency of dye‐sensitized solar cells simultaneously, Au nanoflowers were prepared and used to cover the entire TiO₂ film. Deposition of Au nanoflowers around the TiO₂ film formed a light‐scattering “box” that covered the entire TiO₂ film. Compared with a light‐scattering layer that only covers the top surface of TiO₂, the Au‐nanoflowers box exhibited better light‐harvesting efficiency due to omnidirectional light scattering, faster electron transport (attributed to the formation of electron channels between the metallic Au nanoflowers and the electron‐collection electrode), and slower charge recombination. As a consequence, the short‐circuit photocurrent and open‐circuit photovoltage were both enhanced significantly, which improved the power conversion efficiency from 8.12 to 10.91 % (34 %) when an Au‐nanoflowers box was wrapped around the photoanode.     

阳极氧化法制备二氧化钛纳米管及其荧光性质

室温下采用电化学阳极氧化法在NaF、Na₂SO₄和H₂SO₄的混合溶液中用化学处理后的纯Ti片表面组装了一层结构高度有序的高密度TiO₂纳米管阵列。考察了几种主要的实验参数(阳极氧化电压、温度、电解液浓度)对TiO₂纳米管阵列形貌和尺寸的影响，探讨了二次阳极氧化对纳米管形貌的改善。对TiO₂纳米管阵列进行扫描电子显微镜(SEM)和荧光(PL)分析，探讨其生长机理。结果表明，孔径随阳极氧化电压的升高而变大，温度、电解液浓度影响反应过程中电流密度的大小；二次阳极氧化得到的纳米管的有序性有所改善，孔径大小更为均一，并且发现TiO₂纳米管的荧光具有量子效应。