Ti Foil Research Articles

Effect of Ti foil size on the micro sizes of anodic TiO2 nanotube array and photoelectrochemical water splitting performance

Anodic TiO2 nanotube (NT) array is promising for the flexible and efficient photoanode in photoelectrochemical water splitting (PECWS) cell. However, the photocurrent response of pristine anodic TiO2 NT photoanode in literature has a ca 50 times difference, viz. from 0.05 to 1 mA/cm2. Improvement of the pristine TiO2 NT is the base for achieving a high efficient anode. Here, we examine the size effect in different scale on the PECWS performance with manipulating the macro size of the Ti foil. With decrease of the Ti foil size from 6 to 1 cm2, corresponding to the anodic TiO2 NT growth active area of 3.45 to 0.65 cm2, the photocurrent response increased by 50.6%, achieving 1.13 mA/cm2 at 1.23 VRHE (V versus reversible hydrogen electrode). The Ti foil size also significantly influences the micro sizes of the nanotubes including crystallite size, double wall thickness, inner diameter and tube length, which have profound effects on WS efficiency. The relationships between involved length scales, a span of six orders of magnitude from ten nanometers (10−8 m) to centimeter (10−2 m), and the PECWS efficiency is analyzed and discussed. Transient i-t curves are used to represent the chemical kinetics during the growth of anodic TiO2 NT array. Finally, photon capture scheme is proposed to explain the physics behind the multi length scale effect of the TiO2 NT photoanode. The need of quantitative models during the scale-up of the PECWS process is stressed.

Wireless Anodization of Ti in Closed Bipolar Cells

AbstractIn this work, the anodization of Ti foils in closed bipolar cells is shown for the first time. Depending on the applied potential, i. e. direct or alternating potential, TiO2 nanotube (TNT) layers can either be prepared on one side or on both sides of a Ti foil. It is shown that due to the use of closed bipolar cells, potentials with different amplitudes can be applied within the individual two half‐cells. Additionally, different electrolytes can be used for the anodization of the two sides of a Ti substrate. Thus, the TNT layers obtained under alternating potential on both sides of a Ti foil can have completely different dimensions, i. e. TNT diameter and TNT layer thickness. Furthermore, by employing alternating potentials, black TNT layers can be synthesized on the side of the Ti foil, while being reduced during the last anodization step at negative potentials.

Optimization of a device for positron moderation based on a magnetic bottle

The design optimization of a magnetic bottle device for high-efficiency positron moderation is described herein. The interaction between positrons and matter, including positron tracking, was performed via GEANT and COMSOL simulation. Optimization was performed for a 10 kW power supply for the excitation of two magnetic coils and were established geometry sizes of the device, namely a chamber with a radius of 100 mm and a length of 300 mm. The irradiation of a Ti foil with a thickness of 1 ÷ 10 μm at the TR19 cyclotron for 8 h with a proton current of 10 μA can produce 48V with an activity of 6 ÷ 60 MBq. Given such a source of fast positrons for use in the optimized magnetic bottle device, a slow positron beam intensity of 2 ÷ 10×104 s−1 can be achieved.

Strengthening mechanisms of combined alloying with carbon and titanium on laser beam welded joints of molybdenum alloy

Molybdenum (Mo) and its alloy have great potential in the nuclear power field, but the low strength of fusion welding joints limits its engineering application. By adding two alloying elements in combination, namely carbon (C) and titanium (Ti), this study fulfilled the goal of improving properties of the heat affected zone (HAZ) while strengthening the fusion zone (FZ) of the joint. The alloying process is as follows: the base metal (BM) was first carburized then Ti foil was preset at the welding position and finally laser welding was carried out. The scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron backscatter diffraction (EBSD) and nanoindentation were utilized to analyze mechanical properties and microstructures of the FZ and HAZ of the joint obtained by combined alloying with C and Ti. Moreover, the joint obtained by combined alloying was comparatively analyzed with those alloying only by C or Ti. Combined alloying can increase the maximum tensile strength to 406.6 MPa and strain to 6.6%, respectively. TiC phases as spherical particles with diameter ranging from tens to one hundred of nanometers can be precipitated in the FZ obtained by combined alloying playing a role of second-phase strengthening in Mo. Furthermore, Mo 2 C phases can be clearly observed at the grain boundary in the HAZ of the joint obtained by combined alloying. Mo 2 C is coherent or semi-coherent with the Mo matrix and can also have the second-phase strengthening effect. Combined alloying shows a new idea to strengthen Mo and its alloy welded joints. • The tensile strength and strain of joint by combined alloying with C and Ti can reach to 406.6 MPa and 6.6%, respectively. • TiC particles are precipitated in the FZ and Mo 2 C phases are precipitated in the HAZ obtained by combined alloying. • TiC in the FZ and Mo 2 C in the HAZ can play the role of the second phase-strengthening for the joints.

Evaluation of the Titanium Substrate Effect on the Morphology of Anodic TiO2 Nanotubes

We report the synthesis of novel titanium dioxide nanotube arrays (TNAs) via an anodization process using five different kinds of titanium foils as working electrodes. This reveals that the morphology of TNAs in impacted by the purity, conductivity, and mechanical properties of the titanium sheets. Under the same electrochemical conditions, when titanium foil with purity of 99.7% was used as the working electrode, the TNAs with maximum aspect ratio was obtained compared to that prepared by low purity metal substrate. We also track and observe the morphology of the secondary oxidized TNAs, and demonstrate the relationship with different purites of Ti foils. The fact that the adhesion of anodic TNAs to Ti substrates closely relates to the residual stress of substrates is also revealed. Specifically, cathodic pulse doping results show that the black appearance of TNAs is strongly dependent on the purity of different Ti foils.

Low temperature deposition of BiFeO3 films on Ti foils for piezoelectric applications

Predominantly (100)-oriented BiFeO3 films with excellent ferroelectric and piezoelectric properties were successfully fabricated on Ti foils via RF-magnetron sputtering at 450 °C. Well-saturated P-E loops with a high remnant polarization (Pr ~72 μC/cm2) and a large built-in field (~145 kV/cm) were observed in the BiFeO3 films. A large transverse piezoelectric coefficient (|e31,f| ~ 2.2 ± 0.2 C/m2) and a decent dielectric property (εr~260–270, tanδ~1.6–2.0%), together with a remarkable fatigue-resistance (~1.1% loss of |e31,f| after 1.2 × 106 piezoelectric actuation cycles) were demonstrated in patterned BiFeO3-Ti cantilevers. These results indicate a great potential of BiFeO3 films as piezo-active components in metal-based micro-electro-mechanical systems (MEMS).

Synthesis of CeVO4-V2O5 nanowires by cation-exchange method for high-performance lithium-ion battery electrode

In the current work, a facile and scalable strategy, based on a cation-exchange and heat-treatment route, is developed to fabricate CeVO4-V2O5 nanowires on Ti foil. The CeVO4-V2O5 nanowires are obtained by the cation-exchange of the sodium vanadate (Na5V12O32) nanowires as precursor in cerium chloride and the sample obtained by heat-treatment at 300 °C has high-performance lithium storage properties. In addition, the microstructure, phase composition and chemical valence of CeVO4-V2O5 nanowires are characterized in detail. After 50 cycles, the CeVO4-V2O5 electrode reaches a high reversible capacity of approximately 487 mAh g−1 at a current density of 30 mA g−1. Moreover, the cation-exchange method also paves an efficient and controllable route for the synthesis of other rare earth vanadate-V2O5 composites.

A low temperature synthesis of Ti/TiO2/Fatty Acid/GOx/ZnO and its evaluation for amoxicillin bio-photo-catalytic degradation

A novel strategy for improving the synthesis medium of TiO2 nanowires has been taken. The findings show that the addition of transformer oils leads to more successful results than enhancing the conductivity of fatty acids. Complete degradation of amoxicillin is attained by a mixture of stearic acid-coconut oil (S/CO). Meanwhile, the Ti foil self-hydrolysis can be possible by designing the synthesis time and temperature. Glucose oxidase (GOx) has been cross-linked to TiO2 for situ generation of H2O2. The effect of glutaraldehyde dosage and ZnO/GOx ratio have been investigated. The biophotocatalysts have been characterized by XRD, SEM, FTIR, DSC, TEM, DLS, and BET. It is noteworthy that the synthesis waste remains crystalline with no considerable change in the melting temperature, which allows its reuse. Such a result is of great economic and environmental value for the reduction of chemicals. Finally, the mechanism of biophotocatalytic degradation of amoxicillin over Janus Ti/TiO2/Fatty Acid/GOx/ZnO is discussed.

Microstructural and mechanical properties of CFC composite/Ti6Al4V joints brazed with Ag–Cu–Ti and refractory metal foils

Microstructural and mechanical properties of CFC composite/Ti6Al4V joints brazed with Ag–Cu–Ti and refractory metal foils

Application of response surface method (RSM) to investigate the effects of process parameters on the microstructure and shear strength of TZM/graphite joints bonded by using spark plasma sintering

The joint of TZM/graphite with Ti foil as the interlayer was successfully obtained by using gradient sintering process of spark plasma sintering (SPS). The response surface method (RSM) based on Box-Behnken design was applied to statistically specify the effects of the bonding temperature (T), bonding pressure (P), holding time (t) and thickness of the interlayer (h) on the shear strength of TZM/graphite joint. The optimum process parameters of T = 1450 °C, P = 17.2 MPa, t = 0.8 h and h = 109 μm were performed to obtain the highest shear strength of 53.6 MPa, which demonstrated the RSM was an excellent tool to implement and tailor the shear strength of the TZM/graphite joint. The excellent shear strength can be ascribed to (βTi, Mo) solid solution crossing each other at the interface, formation of finger-like TiC and little defect in the joint. The stress concentration at the interface between graphite and the TiC layer was evidently larger than that between (βTi, Mo) solid solution and TZM, which led to the occurrence of the shear fracture in the region of TiC phase.

Performance of tantalum as plasma electrode material in negative hydrogen ion sources

The negative hydrogen ion current and the electron current extracted from arc discharge negative ion sources exhibit different characteristics when the discharge filament material or the plasma electrode material is changed. The knowledge of these characteristics is of importance for the proper design of an efficient H− ion source. We investigated the effect due to tungsten (W) and tantalum (Ta) adsorption on a stainless-steel plasma electrode and compared the results with the performance of the plasma electrodes covered by Ta and Ti foils. The result showed that freshly deposited Ta enhanced the H− ion current and reduced the co-extracted electron current in the same way as a caesium adsorbed film.

Scalable and Controllable Synthesis of Interface-Engineered Nanoporous Host for Dendrite-Free and High Rate Zinc Metal Batteries.

Rechargeable zinc (Zn)-ion batteries are regarded as highly prospective candidates for next-generation renewable and safe energy storage systems. However, the uncontrolled dendrite growth of the Zn anode impedes their practical application. Here, a scalable and controllable approach is developed for converting commercial titanium (Ti) foil to 3D porous Ti, which retains good resistance to corrosion, high electrical conductivity, and excellent mechanical properties. Benefiting from a spontaneous ultrathin zincophilic titanium dioxide (TiO2) interfacial layer and continuous 3D structure, the 3D porous Ti can act as an effective host to achieve a 3D Ti/Zn metal anode. By ensuring homogeneous nucleation, uniform current distribution, and volume change accommodation, the dendritic growth of 3D Ti/Zn metal anode is effectively inhibited with stable Zn plating/stripping up to 2000 h with low polarization. When conjugated with a 3D sulfur-doped Ti3C2Tx MXene@MnO2 nanotube cathode, a high rate and stable Zn cell is achieved with 95.46% capacity retention after 500 cycles at a high rate of 5 A g-1. This work may also be interesting for researches in porous metals and other battery systems.

Synthesis and Photochemical Properties of Monolithic TiO2 Nanowires Diode.

In this paper, the structural and photochemical properties of a monolithic photochemical diode are discussed. The present structure is composed, from the top to the bottom, of a TiO2 nanowire layer, a TiO2 film, a Ti foil, and a porous layer made of Pt nanoparticles. The synthesis of the nanowires was simply carried out by Au-catalysed-assisted process; the effects of the annealing temperature and time were deeply investigated. Morphological and structural characterizations were performed by scanning electron microscopy and Raman spectroscopy. The analyses showed the rutile structure of the TiO2 nanowires. The photocatalytic properties were studied through the degradation of methylene blue (MB) dye under UV light irradiation. The nanowires induced an enhancement of the photo-degradation rate, compared to TiO2 in a bulk form, due to an increase in the surface area. Moreover, the presence of a nano-porous Pt layer deposited on the rear side of the samples provided a further increase in the MB degradation rate, related to the scavenging effect of Pt nanoparticles. The overall increment of the photo-activity, due to the nano-structuration of the TiO2 and to the presence of the Pt layer, resulted a factor 7, compared to the bulk reference. In addition, photovoltage measurements allowed to assess the effects of TiO2 nano-structuration and Pt nanoparticles on the electron accumulation.

A study of the foil explosion in vacuum using spectral streak camera diagnostics

The foil explosion in vacuum was studied experimentally using a spectral streak camera. The experiment was performed with Cu, Al, Ni, and Ti foils of thickness 6 μm at a current density rise rate of ∼6 × 105 A/(cm2 ns). For all exploded foils, a plasma corona was formed in the gas desorbed from the foil surface when the voltage across the discharge gap reached the collapse voltage. In the Cu, Al, and Ni foil explosions, the specific deposited energy εdep was sufficient for complete melting but insufficient for vaporization of the foil material. However, the streaked spectra obtained for these foil explosions contained the foil material lines that appeared 80–200 ns after tcoll. The authors hypothesize that these lines appeared as a result of the decaying of the metastable liquid state of the exploded foil metal, which took place at a certain time after the core was shunted. In the Ti foil explosion, the deposited energy was insufficient to melt the metal, the transition to the metastable liquid state did not occur, and the discharge plasma spectrum did not contain lines of the foil material.

Improved quality of resistance spot welded joints for molybdenum sheets in lap configuration by adding titanium interlayer

Resistance spot welding (RSW) exhibits low heat input and high efficiency. However, because Mo exhibits low resistivity and high hot strength, it is difficult to effectively combine the resistance spot welded joints of Mo. The lap joint of 1-mm-thick Mo sheets was welded using RSW. Moreover, the welding parameters (current, welding duration, and electrode force) were optimised. Using Ti foil as the interlayer, the influence of the alloying element on the resistance spot welded joint of the Mo sheets was explored. The results indicate that the success rate of welding can be improved by utilising a high current and short welding duration, and increasing the electrode force causes reduced contact resistance and further failure of the welding. In addition, an excessively high electrode force may result in electrode adhesion. Here, a current of 20 kA, welding duration of 0.4 s, and electrode force of 3726 N were used as the optimised parameters. The joint obtained under the parameters can withstand the highest shear load (about 2.20 kN); the shear load of the joint obtained after adding the Ti interlayer (thickness: 0.03 mm) increases by approximately 54%. After adding the Ti foil, the heat input on the interface increased and Ti melted to form metallurgical bonding with Mo. Under these conditions, the interfacial strength increased significantly. During the tensile–shear test, the heat-affected zone of Mo is fractured, in which the shear fracture is subjected to brittle failure.

An experimental platform for studying the radiation effects of laser accelerated protons on mammalian cells

An experimental platform was designed to study the effects of laser accelerated protons (LAPs) on mammalian cells. The protons, in the MeV energy range, originate from the rear side of a thin 5 µm Ti foil target following the interaction with a high power laser pulse and are accelerated by the target normal sheath mechanism. A tape Ti foil target was developed, allowing a shot repetition rate of up to 5 Hz, which corresponds to the rate of the laser system. A dipole magnet arrangement was used for energy dispersion and to separate the proton burst from electrons and x rays. The absorbed radiation dose at the cell port was measured with CR39 plastic detectors and calibrated imaging plates. An epifluorescence microscope with compact open-beam optics was developed to image live cells and their spatiotemporal properties during and after irradiation. To demonstrate the functionality of all components of the platform, biological proof of concept experiments were carried out using two suspension (Jurkat and Ramos) and two adherent (HeLa and A-549) cell lines. A multitude of biological procedures and analytical techniques were established on-site or in laboratories nearby. For example, we analyzed DNA double-strand break (DSB) induction and repair by detecting the γH2A.X signal by fluorescence microscopy and flow cytometry. The observed dose-dependent increase in DSB induction confirms that DNA damage is induced in cells after exposure to LAPs.

MoS2 ile dekore edilmiş TiO2 Nanotüp Elektrotların Sentezi, Karakterizasyonu ve Fotoelektrokimyasal Özellikleri

In this research, TiO2/MoS2 nanocomposite electrodes were synthesized to investigate the photoelectrochemical performances. Firstly, TiO2 nanotubes were fabricated by anodic oxidation on Ti foil. Then, MoS2 nanostructures were synthesis by hydrothermal method on TiO2 nanotubes. The prepared nanocomposite films were characterized by using X-Ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The transient photocurrent response was analyzed to investigate photoelectrochemical activity of electrodes. The results show that TiO2 nanotube arrays coated with MoS2 nanostructure homogeneously. Furthermore, TiO2/MoS2 nanocomposite electrode were shown better photoelectrochemical activity then bare TiO2 electrode.

Fabrication and characterization of NiTif-SiCf synergistically reinforced (Al3Ti+Al3Ni)-based metallic-intermetallic laminated composite

In this work, a novel NiTif-SiCf synergistically reinforced (Al3Ti+Al3Ni)-based metallic-intermetallic laminated (NiTif-SiCf/(Al3Ti+Al3Ni)-MIL) composite was designed and synthesized using NiTi and SiC fibers, Ti and Al foils with the “Ti (TC4)-NiTif-Al-Ti (TA1)-Al-SiCf-Ti (TC4)” stacked unit by hot pressing sintering process in vacuum. The TA1 foils as barrier (Tib) are favorable to promote the consumption of Al, meanwhile, allow NiTif and SiCf to co-exist in one intermetallic layer. SEM, EDS, XRD and EBSD techniques were employed to investigate microstructure features, phase constituents and growth kinetics of the NiTif-SiCf/(Al3Ti+Al3Ni)-MIL composite. Besides, the mechanical performances of the composite were detected through compressive tests. The results showed that the newly formed phases in the composite consisted of Al3Ti, Al3Ti0.8V0.2 and Al3Ni, which were obtained from the reactions of Ti/Al and NiTif/Al, resulting in the generation of inhomogeneous intermetallic layer. In addition, NiTif and SiCf, lined up respectively, were distributed uniformly in one intermetallic layer along parallel orientation and the oval shaped eutectic areas were in-suit formed around NiTif by reaction of NiTif/Al. While Tib layers were disappeared between NiTif and SiCf due to the complete reaction of Tib/Al, and were replaced by Al3Ti and Al3Ni phases. However, the Al3Ti grains at this area grew abnormally by devouring the surrounding grains after recrystallization, which were harmful to the strength of the composite. Furthermore, the kinetic calculation results showed that the growth of NiTif/Al and Tib/Al interfacial layers are governed solely by chemical reaction mechanism at 630 °C. Moreover, the NiTif-SiCf/(Al3Ti+Al3Ni)-MIL composite acquired superior specific strength and ductility in both perpendicular and parallel directions, which were attributed to the pull-out and breakage of SiCf and NiTif, as well as crack deflection at interfaces.

Low Temperature Deposition of Bifeo3 Films on Ti Foils for Piezoelectric Applications

Predominantly (100)-oriented BiFeO 3 films with excellent ferroelectric and piezoelectric properties were successfully fabricated on Ti foils via RF-magnetron sputtering at 450 °C. Well-saturated P-E loops with a high remnant polarization ( P r ~72 μC/cm 2 ) and a large built-in field (~145 kV/cm) were observed in the BiFeO 3 films. A large transverse piezoelectric coefficient (| e 31,f | ~ 2.2± 0.2 C/m 2 ) was demonstrated in patterned BiFeO 3 -Ti cantilevers, together with a high piezoelectric figure of merit (~2.1 GPa), a large voltage response (~0.96 GV/cm) and a remarkable fatigue-resistance (~1.1% loss of | e 31,f | after 1.2×10 6 actuation cycles). These results indicate a great potential of BiFeO 3 films as piezo-active components in metal-based micro-electro-mechanical systems (MEMS).

Ag/SnO2/TiO2 nanotube composite film used in photocathodic protection for stainless steel

A TiO2 nanotube film was fabricated on a Ti foil via anodization, SnO2 quantum dots were deposited on the film by hydrothermal treatment, and then Ag nanoparticles were formed on the SnO2/TiO2 film by pulse electrodeposition to obtain a Ag/SnO2 co-modified TiO2 composite photoanode with good photocathodic protection performance and charge storage ability. The properties of the composite film were investigated by surface analyses, UV–vis and fluorescence spectroscopies, and photoelectrochemical measurements. The results showed that the light absorption of the Ag/SnO2/TiO2 film was extended into the visible region compared with the TiO2 film. The photocurrent intensity of the composite film was two times as high as that of the TiO2 film. The composite photoanode under illumination by white light made the potential of the coupled 403 stainless steel (403SS) in a 0.5 M NaCl solution drop by 475 mV in contrast with its corrosion potential, showing an enhanced photocathodic protection effect. It is noteworthy that the 403SS potential was still 270 mV lower than the corrosion potential within 22.5 h after cutting off the illumination, demonstrating that the cathodic protection could be maintained through the charge storage ability of the composite photoanode.