Morphology Of Nanotubes Research Articles

Comparison of the conductive properties of polyester/viscose fabric treated with Cu nanoparticle and MWCNTs

In this work, the specimen of the fabrics (polyester/viscose blend) was prepared. At first, the samples were placed under microwave radiation at different times, and then the optimum condition of treated fabrics (8 min) was selected for treatment. The physical properties and surface morphology of Cu nanoparticle and multi-wall carbon nanotubes (MWCNTs) with different percentages were measured using dispersing agent, washing performance, stability, and physical properties of the fabric. The image of surface morphology’s specimens was also photographed by scanning electron microscopy (SEM). Afterwards, we measured the specimens’ electrical conductivity properties, according to AATCC 2005-76 standards, and subsequently, K/S, %R, and Lab value of specimens was analyzed using reflection spectrophotometer. In fact, the results indicated that optimum electrical resistivity, which was also the aim of the study, is 9% one weight of fabric (o.w.f.) nanoparticles on the fabric and that electrical resistivity for the values of 9% o.w.f. for CNT is slightly greater than Cu.

An image-driven finite element modeling method for evaluating the stress and strain distribution in carbon nanotubes/epoxy composites

Due to the complex morphology of carbon nanotubes (CNTs) in an epoxy resin, it is difficult to establish finite element (FE) models using common methods. Therefore, this study introduces an approach using real TEM images of CNTs/epoxy composites to establish FE models and obtain real stress and strain distributions. Two kinds of multi-walled carbon nanotubes (MWCNTs), unmodified and plasma-treated MWCNTs, were also used to investigate the effects of the dispersion state of MWCNTs on the mechanical properties of MWCNTs/epoxy composites. Due to the real-shape models, the simulation results clearly showed that well-dispersed MWCNTs more effectively transferred stresses, and thus reduced localized stress concentration and improved the deformation resistance in composites. The composite with poorly-dispersed MWCNT exhibited a higher stress concentration at MWCNTs and more severely strained areas in the epoxy resin. In this case, debonding was very likely to occur at the interface of the two substances, and caused the formation of preliminary cracks in the components.

Ullmann Reactions of Carbon Nanotubes-Advantageous and Unexplored Functionalization toward Tunable Surface Chemistry.

We demonstrate Ullmann-type reactions as novel and advantageous functionalization of carbon nanotubes (CNTs) toward tunable surface chemistry. The functionalization routes comprise O-, N-, and C-arylation of chlorinated CNTs. We confirm the versatility and efficiency of the reaction allowing functionalization degrees up to 3.5 mmol g−1 by applying both various nanotube substrates, i.e., single-wall (SWCNTs) and multi-wall CNTs (MWCNTs) of various chirality, geometry, and morphology as well as diverse Ullmann-type reagents: phenol, aniline, and iodobenzene. The reactivity of nanotubes was correlatable with the nanotube diameter and morphology revealing SWCNTs as the most reactive representatives. We have determined the optimized conditions of this two-step synthetic protocol as: (1) chlorination using iodine trichloride (ICl3), and (2) Ullmann-type reaction in the presence of: copper(I) iodide (CuI), 1,10-phenanthroline as chelating agent and caesium carbonate (Cs2CO3) as base. We have analyzed functionalized CNTs using a variety of techniques, i.e., scanning and transmission electron microscopy, energy dispersive spectroscopy, thermogravimetry, comprehensive Raman spectroscopy, and X-ray photoelectron spectroscopy. The analyses confirmed the purely covalent nature of those modifications at all stages. Eventually, we have proved the elaborated protocol as exceptionally tunable since it enabled us: (a) to synthesize superhydrophilic films from—the intrinsically hydrophobic—vertically aligned MWCNT arrays and (b) to produce printable highly electroconductive pastes of enhanced characteristics—as compared for non-modified and otherwise modified MWCNTs—for textronics.

Anodic TiO2 nanotube supercapacitors enhanced by a facile in situ doping method

In this work, the capacitive properties of anodic TiO2 nanotubes were enhanced by a facile in situ doping method. The tuning of TiO2 anodization was realized by adding Fe(NO3)3 into the aqueous HF solution as the dopant. The morphology, structure, chemical composition and capacitive properties of the as-prepared TiO2 nanotubes were characterized by various methods. It is found that N, F, and Fe elements can be doped into TiO2 nanotubes during the anodization process. The effect of doping concentration on the capacitive properties of TiO2 nanotubes was also investigated. With the optimum doping concentration of ~ 0.02 M, the doped TiO2 nanotubes exhibited a capacitance of 1.11 mF cm−2 at the scan rate of 100 mV s−1, much higher than that of the undoped TiO2 nanotubes. The X-ray photoelectron spectroscopy (XPS) results indicated the presence of N, F, and Fe in the TiO2 lattice and absorbed F on the TiO2 surface, both of which are believed to be the cause for the capacitance enhancement of the doped TiO2 nanotubes.

Titania nanotube morphologies for osseointegration via models of in vitro osseointegrative potential and in vivo intramedullary fixation.

As total joint replacements increase annually, new strategies to attain solid bone-implant fixation are needed to increase implant survivorship. This study evaluated two morphologies of titania nanotubes (TiNT) in in vitro experiments and an in vivo rodent model of intramedullary fixation, to simulate joint arthroplasty conditions. TiNT surfaces were prepared via an electrochemical etching process, resulting in two different TiNT morphologies, an aligned structure with nanotubes in parallel and a trabecular bone-like structure. in vitro data showed bone marrow cell differentiation into osteoblasts as well as osteoblastic phenotypic behavior through 21 days. In vivo, both TiNT morphologies generated greater bone formation and bone-implant contact than control at 12 weeks, as indicated by μCT analyses and histology, respectively. TiNT groups also exhibited greater strength of fixation compared to controls, when subjected to wire pull-out testing. TiNT may be a promising surface modification for promoting osseointegration.

Characterization of titanium oxide nanotubes growth through anodization in organic solvents

The titanium oxide nanotubes have generated great interest in recent years because to the wide variety of applications in which they are used. The reason for this is the excellent surface properties that this material gets after of grow in the anodizing process. These properties can easily modify the electrochemical anodizing process. For this reason, we have analyzed the effect of electrolyte on the morphology and corrosion resistance of titanium oxide nanotubes grown at glycerol with 0.3% w/w ammonium fluoride and 2% v/v distilled water at 30 volts for 1 hour and ethylene glycol with 0.3% w/w ammonium fluoride and 2% v/v distilled water at 40 volts for 30 minutes. The morphology of the surfaces is observed by scanning electron microscopy. The resistance to corrosion of the samples is evaluated by potentiodynamic polarization curves in Hanks solution at 37 °C. The results of the nanotubes grew in glycerol have a length of 0.7 μm with a morphology of the bamboo type, while the nanotubes grown in ethyleneglycol they have a length of 3.3 μm and their morphology is smooth wall. Regarding the corrosion rate, it was determined that the nanotubes grown in glycerol have a higher corrosion rate. Because to these low corrosion rates it is considered that the two surfaces can be used as alternatives to modify orthopedic implant materials.

Fabrication of TiO2-Nanotube-Array-Based Supercapacitors.

In this work, a simple and cost-effective electrochemical anodization technique was adopted to rapidly grow TiO2 nanotube arrays on a Ti current collector and to utilize the synthesized materials as potential electrodes for supercapacitors. To accelerate the growth of the TiO2 nanotube arrays, lactic acid was used as an electrolyte additive. The as-prepared TiO2 nanotube arrays with a high aspect ratio were strongly adhered to the Ti substrate. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results confirmed that the TiO2 nanotube arrays were crystallized in the anatase phase. TEM images confirmed the nanotublar-like morphology of the TiO2 nanotubes, which had a tube length and a diameter of ~16 and ~80 nm, respectively. The electrochemical performance of the TiO2 nanotube array electrodes was evaluated using the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD) measurements. Excellent electrochemical response was observed for the electrodes based on the TiO2 nanotube arrays, as the cells delivered a high specific capacitance of 5.12 mF/cm2 at a scan rate of 100 mV/s and a current density of 100 µA/cm2. The initial capacity was maintained for more than 250 cycles. Further, a remarkable rate capability response was observed, as the cell retained 88% of the initial areal capacitance when the scan rate was increased from 10 to 500 mV/s. The results suggest the suitability of TiO2 nanotube arrays as electrode materials for commercial supercapacitor applications.

Rayleigh‐Instability‐Induced Transformation for Confined Polystyrene Nanotubes Prepared Using the Solvent‐Vapor‐Induced Wetting Method

AbstractPolystyrene (PS) nanotubes prepared using the solvent‐vapor‐induced wetting method with anodic aluminum oxide templates are for the first time applied to study the thermal stabilities of polymer nanotubes confined in cylindrical geometries. The morphologies of the PS nanotubes and the corresponding transformed PS nanostructures driven by the Rayleigh instabilities after thermal annealing treatments are characterized by scanning electron microscopy. Morphology diagrams of the Rayleigh‐instability‐induced nanostructures for PS nanotubes prepared via the solvent‐vapor‐induced wetting method and the solution wetting method are constructed to study the differences in kinetics for samples using different wetting methods. Slower transformation kinetics for the PS samples prepared by the solvent‐vapor‐induced wetting method than those prepared by the solution wetting method are observed, indicating the better thermal stabilities and the relatively denser packings of the polymer chains in the nanopores for the PS samples prepared using the solvent‐vapor‐induced wetting method.

Synergistic effect of control parameters and morphology on synthesis and performance of the Al2O3/MWCNT composite as a promising capacitor material

The functional ceramic/CNT composites were investigated using the alumina (Al2O3)/multiwall carbon nanotube (MWCNT) composite as a promising capacitor material based on its electrochemical properties, mesoporous morphology, and aligned MWCNT network. The aligned morphology of the carbon nanotubes in alumina matrix annealed at 900 °C resulted in increased surface area (609.55 m2 g−1), hardness (11 GPa), and Young’s modulus (85.88 GPa). The electrochemical properties of the Al2O3/MWCNT composite were investigated by galvanostatic charge–discharge, cyclic voltammetry, and electrochemical impedance spectroscopy measurements. The MWCNT/Al2O3 composite displays appreciable specific capacitance (183.33 F g−1), energy density (9.16 Wh kg−1), and power density (2.99 kW kg−1) with the addition of 5 wt.% MWCNT. The cycling characteristics of the electrode material show excellent stability up to 1000 charge/discharge cycles with MWCNTs playing the role of the current collector while mesoporous alumina adds to the capacitive performance of the electrode. The alignment of MWCNTs within the alumina matrix changed into accountable for the electrochemical properties of the composite. The results obtained and the ceramic film fabrication technique used in this work provide unflinching confidence that this composite material will be utilized for the fabrication of cost-effective devices for energy storage applications.

Partially disordered TiO2 nanotube photonic crystal: randomness characterization and tuning of reflected scattering light

Introducing disorder into a periodic nanostructure can lead to specific optical behaviors. We present a method of anodic oxidation by adjusting the applied voltage and process time to introduce disorder to TiO2 nanotubes. The surface morphology of TiO2 was numerically investigated according to the morphologies measured with a scanning electron microscope by imaging processing and a statistical method. TiO2 nanotubes obtained under different fabrication conditions have various tube radii ranging from 20–40 nm and wall thicknesses ranging from 20–70 nm. We also evaluated the degree of disorder of the tube radius of the TiO2 nanotubes. The reflected scattering light distributions of laser sources were optically measured at different observing distances, which indicate that the presence of nanotubes enhances the scattering effect, reducing the scattered light intensity by more than 75%, and provide the relationship between the scattering effect and surface morphology of nanotubes. This discovery offers TiO2 nanotubes important application prospects in optical limiting and light confinement, such as stealth coating.

Morphological Evolution of Fe-Oxy-Hydroxide Nanotubes During Electrodeposition

Background: Ordered arrays of 1D iron(oxyhydr)oxide nanostructures have potential applications in magnetic recording mediums, lithium batteries, supercapacitors, and thermal production of α-, β-, γ-type Fe2O3. Large surface areas with three-dimensional architectures, such as nanotubes, are encouraged because the easy access of ion, gas, liquid and radiation assures high ion exchange capacity, sensing and catalytic activities. Objective: In this work, the morphological evolution of Fe-oxyhydroxide electrodeposition inside AAM pores has been followed for the first time by selecting two relevant electrochemical conditions of synthesis producing high quality morphologies of nanotubes. Methods: Iron(oxyhydr)oxide nanotubes have been synthesized by cathodic electrodeposition at a constant current in classic three-electrode cell. Two different electrolytic baths have been studied: (i) an aqueous bath consisting of 5 mM FeCl3+5 mM KF+0.1 M KCl+1 M H2O2 (H-Fe) and (ii) an ethanolic bath consisting of 0.3 M FeCl3 + 0.1 M KCl (Et-Fe). Results: XRD, Raman and SEM results on the iron(oxyhydr)oxide nanotubes suggest different mechanisms of chemical precipitation mechanisms in Et-Fe alcoholic solution (dehydration and rearrangement within the ferrihydrite aggregates) and H-Fe aqueous solution (dissolution/ reprecipitation). The morphological evolution of the growing nanostructure to nanotubes inside AAM in the two baths agrees very well with the overpotential vs. time curves, the kinetic growth of the nanotubes arrays and a growth mechanism governed by the relative mass transfer processes involving both OH- and Fe ions. Conclusion: The morphological evolution of Fe-oxyhydroxide cathodic electroprecipitation inside AAM pores in two relevant electrochemical baths containing Fe(III) (aqueous/H-Fe and alcoholic/Et- Fe) has been followed for the first time by a comprehensive SEM analysis accompanied by electrochemical, structural and kinetic growth of the nano-electrodeposits. : The detailed SEM results collected in this work allowed to recommend template electrogeneration of base in ethanol solution containing Fe(III) chloride as a relevant procedure to obtain high-quality, compact and well-ordered Fe oxy-hydroxide nanotubes.

SINTESIS TiO2/Ti DENGAN TEKNIK ANODISASI DAN UJI AKTIVITAS FOTOKATALIS SEBAGAI ANTIBAKTERI Escherichia coli

Titanium dioxide (TiO2) thin layer on the surface of metal Ti has been successfully synthesized using anodization method by varying the anodization times 30, 45 and 60 minutes. Characterization of TiO2/Ti with FTIR method gives absorption peaks at wave number 457,490 cm-1 and 796,635 cm-1, which is a Ti-O vibration. Visualization TiO2/Ti under SEM showed pores with diameter of 10-45 nm as an indication of the morphology of nanotubes, although the length of tubes have not been obtained. The results of XRD measurement give diffractogram at 2q: 25,337°; 37,891° and 48,074° and characterization DR-UV visible value 3,276 eV band gap which characterize crystalline anatase TiO2 phase. Photocatalytic TiO2/Ti exhibit antibacterial activity Escherichia coli were tested using the method of turbidimetry with a spectrophotometer at wavelength of 600 nm. Photocatalyst TiO2/Ti which are synthesized by anodizing process for 60 minutes have inhibitory bacterial growth better than synthesized for 30 minutes and 45 minutes.

Corrosion behaviour of Ti6Al4V ELI nanotubes for biomedical applications

Surfaces engineering on titanium biomedical alloys aiming for improving bone regeneration, healing periods and increasing lifetime needs for a fundamental understanding of the electrochemical reactions occurring at the interface biomaterial/human fluid. There, electrochemical corrosion plays an important role in implant-tissue interaction. The aim of this study is to investigate the effect of different TiO2 surfaces and nanotubes on a Ti6Al4V ELI in their electrochemical corrosion resistance by different electrochemical techniques (open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization). The electrochemical behaviour of native, anodized, nanotubular and annealed nanotubular surfaces were investigated in 1M NaCl solution. The nanotubular topography was obtained by electrochemical oxidation and the annealing treatment allowed at changing the crystalline structure of the oxides. The nanotube morphology, chemical composition, and structure was studied by Field Emission Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray diffraction and Transmission Electron Microscopy respectively. The results show that the anodic oxidation treatment creates a nanotubular topography that increases the surface area and changes the surface chemical composition. The electrochemical corrosion resistance decreased on the as-formed TiO2 tubes compared to the native oxide layer, due to higher surface area and amorphous crystal structure of the passive film. After annealing treatment, the fluoride ions are eliminated, and nanotubular resistance is enhanced through anatase stabilization.

Enhancement in photoelectrochemical ability via re-engineering the band gap of multi-podal titania nanotubes on functionalizing with copper oxide nano-cubes

In this study, multi-podal titania nanotube array (anatase) were fabricated via electrochemical anodization technique on employing third generation electrolyte with suitable and sharp optimization of every anodization parameter. In comparison to conventional titania nanotubes, these nanotubes offer sufficient nanotube wall/electrolyte interface and thereby makes the appreciable reduction in electron hole pair recombination rate by immediate involvement of holes and electrons in oxidation and reduction process, respectively. Furthermore, 85 nm diameter variation in these nanotubes from base diameter 263 nm to top diameter 348 nm makes the incoming light to undergo through graded refractive index which in corresponding increases their light harnessing ability. Although morphological advantage of these nanotubes is being efficiently harnessed in the scattering of incident light but the large band gap 3.2 eV still confines their utility to UV region only. To increase their photo-electrochemical potential under visible light as well, these nanotubes were functionalized suitably with Cu2O nano-cubes without disturbing the nanotube morphology. Under the analysis of their photo-electrochemical potential, the photocurrent density recorded for bare and Cu2O functionalized multi-podal titania nanotube array under visible light source 300 W Xenon lamp (1 sun illumination) was 0.27 mAcm−2 and 0.39 mAcm−2, respectively. The enhancement of ~45% in photocurrent density under visible light illumination is attributed to suitable band edge positions in Cu2O with respect to the band edge positions in TiO2 which in corresponding leads the formation of effective visible light active band gap in the resulting hybrid structure.

Raman spectroscopic study of the influence of voltage-time on titania growth-fast anodized nanostructures

Many studies, focused in TiO2 nanotubes obtained by anodization, uses frequently a NH4F salt concentration from 0.3 – 0.5 wt% and the information about how voltage and time affects to nanotubes morphology, are valid for these concentration, moreover, this range induces a long time of anodized. TiO2 nanotubes were prepared by anodization process of a set of titanium foils in order to study the influence of time and voltage on the morphology of them. The anodization process consists of an organic media of ethylene glycol and 1.2 wt% of NH4F salts, voltage from 5 to 30 V for a time period from 1 to 6 hours, constant potential of 30 V for a time lapse from 10 to 360 minutes and 5 to 480 seconds. All anodized samples are rinsed and annealed to 400 °C by 3 hours to obtain an anatase crystalline structure. The morphological characterization was carried out by Field Emission Scanning Electron Microscopy (FESEM) to verify the presence of the nanostructures: nanopores, nanotubes and nanograss, these nanostructures were identified to appear for a time period from 5 to 480 seconds, 10 to 60 minutes and 1 to 6 hours, respectively. The surface morphology, inner diameter and length of the nanotubes varied with the electrochemical anodization parameters. Raman spectroscopy was used for optical characterization in order to identify the changes in signal intensity and Eg mode Shift and it was observed that intensity suffers an increment and Eg mode suffers a blue shift as a thickness function.

Synthesis by anodisation method, characterization by SEM and EDS, and degradable ability of TiO2 nanotubes.

Obtaining of TiO2 nanotubes could be performed by anodized Ti in fluoride based electrolyte. During the growth of TiO2 nanotubes within the influence of anodizing process of Ti, a certain parameters are required, electrolyte composition, voltage, and time. The TiO2 nanotube array was synthesized electrochemically in a fluoride containing electrolyte by anodisation method of a pure titanium plate. The anodisation procedure was carried out in ethylene glycol electrolyte; the applied voltage was 60 volt. The average inner diameter of the nanotube was (67 nm) and the average outer diameter was (80 nm). Characterization of the nanotubes crystal structure, morphology, and oxide composition were performed via field emission scanning electron microscopy (FE-SEM) and energy dispersion spectroscopy (EDS). Elemental analysis by EDS shows the presence of fluoride, and confirm the formation of TiO2 nanotubes. The results show the possibility of study the distribution of the composition of the tubes elements using the scanning electron microscope-mapping. Synthesized TiO2 nanotubes were applied for the degradation of organic dye methylene blue as water dye pollutant. It is found that rate of degradation of MB in presence of TiO2 nanotubes was greater than in case of degradation without TiO2 nanotubes. It is clear that the main reason for this behavior belongs to the high surface area of TiO2 nanotubes. For (5) ppm of methylene blue, the degradation in presence of TiO2 nanotubes has done completely after (5 hours)

Synthesis of H4Mn5O12 Nanotubes Lithium Ion Sieve and Its Adsorption Properties for Li+ from Aqueous Solution

AbstractLi4Mn5O12 with nanotubes morphology was successfully prepared by hydrothermal and solid phase reaction. The as‐obtained adsorbent was determined by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and N2 ad/desorption technologies. The characterization results indicated that spinel H4Mn5O12 took on two‐dimensional nanotubes morphology with the diameter of pore ∼200 nm, BET surface area is 92.997 m2⋅g−1, and the corresponding pore size centers at 3.4, 35.9 and 156.5 nm. The adsorption experimental results showed that the maximum Li+ adsorption capacity of H4Mn5O12 was as high as 37.0 mg⋅g−1, and the adsorption process fit well with Langmuir model. In addition, adsorption kinetic experimental data were well fitted by the pseudo‐second‐order model, which indicated the adsorption process followed chemisorption involving in ion exchange. The effects of co‐existing cations on lithium recovery suggested that Na+, K+, Ca2+ and Mg2+ ions had very small effect on recovery of lithium. The regeneration of H4Mn5O12 for the multicyclic Li+ adsorption and desorption were also assessed. The result implied that most of Li+ could be desorbed within 40 min, but the adsorption capacity decreased when the number of cycles was five, which indicated that the structure of H4Mn5O12 was needed to be improved. Lithium adsorption onto H4Mn5O12 could be attributed to electrostatic interaction and ion exchange between Li+ and H+ according to the results of adsorption isotherm and kinetics properties.

Correlation between structural and magnetic properties of FeNi nanotubes with different lengths

Fe20Ni80 alloy nanotubes with different lengths of 3 μm, 6 μm, 9 μm, 12 μm and with “caps” were formed using template synthesis in the pores of PET membranes. The “caps” begin to form over individual nanostructures due to uneven growth, when some tubes reach the template surface before the others at the end of active growth stage. The influence of growth mechanism at different formation stages on the nanotube structure and morphology as well as the correlation between their structural properties and magnetic behavior of arrays were comprehensively studied. The structural parameters (crystallinity degree, lattice parameter and microstresses) were demonstrated as a dependence on the nanotubes length. The structural and magnetic correlations with the processes taking place at various stages of nanotubes evolving from nucleation to active growth and to “caps” formation were analyzed. With increasing the nanotube length, the magnetization reversals in parallel and perpendicular magnetic field directions substantially differ which is explained by the formation of easy anisotropy direction of a helical type. The considerable contribution of “caps” to the magnetic properties of nanotubes was demonstrated for the first time.

Polyethylene glycol infused acid-etched halloysite nanotubes for melt-spun polyamide-based composite phase change fibers

The unique tubular structure and morphology of inorganic nanotubes makes them very useful supporting materials for thermal energy storage. Lending these properties in the form of composites together with traditional organic phase change materials (PCMs) can solve the existing energy storage and thermal stability problems in PCMs. Here, the acid-etching halloysite nanotubes (A-HNTs) are prepared and employed as inorganic supporting materials to encapsulate polyethylene glycol (PEG). The N2 physisorption results indicated that the specific surface area and pore volume of A-HNTs increased from 45.4m2/g, 0.243cm3/g to 253.4 m2/g and 0.621 cm3/g before and after acid etching leading to an effective PEG load increase from 50 mass% to 70 mass% of composite PCMs. This increasing encapsulation capacity of PEG had a beneficial effect on the phase change performances and the latent heat of the prepared PEG/A-HNTs composite PCMs which reached 112 J/g (as compared to 70.64 J/g of PEG/HNTs). The temperature- regulating time of heat storage and release process were >500 s and 491 s respectively. Further, the DSC thermograms with 100 thermal cycles and TGA results demonstrated that the PEG/A-HNTs composites had an excellent thermal reliability and stability for preparing phase-change fibers by high-temperature melt spinning. The thermal enthalpy, thermal regulating time and relative temperature difference of resultant PA6/PEG/A-HNTs reached 13.57 J/g, 206 s and 3.2 °C, respectively.

Effect of Acetic and Lactic Acids on the Morphology and Photocatalytic Activity of TiO₂ Nanotubes.

Among different methods for fabricating TiO₂ nanotubes, electrochemical anodizing in organic electrolyte is the most preferred due to the formation of ordered and controllable nanotubes and low cost. However, applying this method needs long synthesizing time of about 6-12 hours. The aim of this research is utilizing acetic and lactic acids as additives which could reduce the synthesis time of TiO₂ nanotubes in organic electrolyte owing to the field supporting effect. The evaluations were conducted using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS) and MB (methylene blue) degradation. The results indicated that both of the mentioned additives increase the growth rate and reduce the resistance of nanotubes, hence, they could improve the electrocatalytic properties and photocatalytic activity of TiO₂ nanotubes. According to the results, increasing the concentration of lactic and acetic acid from 0.1 to 1 M leads to improvement the morphology of TiO₂ nanotubes whilst further increasing creates inverse effect and distorts the morphology.