Compact TiO2 Research Articles

Self-powered Sb2S3 photodetectors with efficient carrier transport enabled by compact vertical TiO2 nanorods.

Antimony sulfide (Sb2S3) photodetectors (PDs) possess extensive application prospects. Efficient carrier transport of a PD significantly affects the detectivity and response speed. Herein, we propose an all-inorganic self-powered Sb2S3 PD based on vertical TiO2 nanorods (NRs). The spray-coated 15-nm TiO2 thin film as a seed layer ensures the growth of compact vertical TiO2 nanorod arrays by the hydrothermal method. One-dimensional TiO2 nanorods facilitate photocarrier separation and transport to enhance device performance. Ultimately, the Sb2S3 PD achieves a responsivity of 0.29 A/W, a specific detectivity of 3.37 × 1012 Jones, and a response time of 7.8 µs, showing great potential in commercial applications.

Exploring the efficiency enhancement of perovskite solar cells by chemical bath depositing SnO2 on mesoporous TiO2 electrode

This study presents a groundbreaking approach to enhance the efficiency of perovskite solar cells (PSCs) by employing Chemical Bath Deposited (CBD) SnO2 on mesoporous TiO2 (m-TiO2) as an electron transport layer (ETL) without a traditional compact TiO2 (c-TiO2) layer between FTO (fluorine-doped tin oxide) and m-TiO2 ETL. Our investigation reveals that this method significantly improves carrier dynamics, as evidenced by reduced time constants compared to traditional ETLs. The CBD SnO2 not only augments electron transport but also effectively reduces defect density in m-TiO2 films. These enhancements are reflected in the improved photovoltaic parameters of the cells, including higher open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and an impressive power conversion efficiency (PCE) exceeding 23.62 %. The study further underscores the scalability of this technology, highlighting advancements in screen printing and chemical bath deposition techniques vital for large-area PSC applications. Remarkably, the uniformity of PCE across large-area cells confirms the efficacy and consistency of this approach, which provides a new and general strategy for preparing high-efficiency PSCs.

Inorganic salts released from polypyrrole nanocapsules on compact TiO2 layer for highly efficient inorganic CsPbI3-type perovskite solar cells

The compact TiO2 serves as a crucial electron transport layer (ETL) for fabricating high-efficiency CsPbI3 solar cells. Modifying TiO2 with inorganic ions is regarded as a simple and effective method to optimize the band energy level, eliminate interface defects, and enhance the crystallinity of the CsPbI3 film. However, inorganic ions risk being washed away by perovskite solvents such as DMF and DMSO. In this work, core–shell inorganic salt (LiCl, NaCl, ZnCl2)@polypyrrole nanocapsules (PPy NCPs) were fabricated as a buffer layer at the interface of TiO2/CsPbI3 layer. The inorganic salts are released from PPy NCPs during the annealing process of the CsPbI3 precursor film, thereby preventing them from being washed away by the DMF/DMSO solvents. Compared to NaCl@PPy NCPs-TiO2, ZnCl2@PPy NCPs-TiO2, and pristine TiO2 films, the LiCl@PPy NCPs-TiO2 exhibited the best electron conductivity and highest Fermi level. The released LiCl not only passivates point defects in TiO2 by forming Li-O-Ti bonds, optimizing the energy level at the TiO2/perovskite interface, but also incorporates into the CsPbI3 lattice, improving its crystallinity. As a result, solar cells based on LiCl@PPy NCPs-TiO2 layer demonstrated a higher PCE of 19.78 %, along with increased open-circuit voltage (VOC) and fill factor (FF) values of 1.161 V and 83.1 %, respectively. Furthermore, the LiCl@PPy NCPs-TiO2 layer also enhanced the stability of CsPbI3 solar cells under humidity conditions.

In situ oxidative growth to form compact TiO2–Ti3C2 heterojunctions for photocatalytic hydrogen evolution

Solar photocatalytic hydrogen production shows promise in addressing global energy and environmental concerns. The limited efficiency of photocatalysts is mainly due to ineffective separation and transfer of photogenerated charges. To improve this, we enhance the TiO2–Ti3C2 heterojunction by in-situ oxidation through interfacial engineering, resulting in a more compact composition. Subsequently, we anchor single-atom Pt at the TiO2–Ti3C2 interface through photo-Ti3C2 reduction. The in-situ growth of TiO2 on Ti3C2 introduces an interfacial driving force for carrier separation and provides a channel for electron transfer from TiO2 to Ti3C2. This further facilitates transfer onto Pt, shortening the migration distance and enhancing the photocatalytic efficiency. The best Pt/TiO2–Ti3C2 composite demonstrates an impressive hydrogen precipitation efficiency of 767 μmol g−1 h−1, surpassing TiO2 and Pt/TiO2 by factors of 12 times and 1.46 times, respectively. Furthermore, we developed a higher efficiency photocatalyst using the molten salt method to avoid the risks associated with conventional hydrofluoric acid etching. This research opens up new possibilities for the preparation of MXenes interface-modified catalysts, offering a valuable avenue for future exploration in the field.

Studies on the development and performance of natural dye-sensitised solar cell

ABSTRACT Dye-sensitised solar cells (DSSCs) have gained popularity as a cost-effective alternative to silicon-based solar cells. The present study, provides a unique approach for the construction of DSSCs using anatase titanium dioxide (TiO2) as the photoelectrode material and natural fruit extracts (blackcurrent and pomegranate) as photosensitisers. To generate a compact and homogenous TiO2 anatase layer, nanoparticles are deposited onto a transparent conducting fluorine-doped tin oxide glass. Subsequently, natural fruit extracts were added to the TiO2 anatase film, functioning as photosensitisers to absorb sunlight and start the electron transfer process. Each fruit extract unique chemical makeup adds to the absorption of various wavelengths, widening the DSSC's light absorption spectrum. A thin graphite coating was applied to a conducting material for the generation of a counter electrode, which completes the DSSC structure. The sensitised TiO2 anatase layer and counter electrode are joined together, with a redox electrolyte filling the gap between them. Current–voltage measurements used to characterise the manufactured DSSC during simulated solar irradiation. The DSSC's efficiency was calculated as 0.4–18% based on the produced photocurrent and incident light intensity. The study’s finding shows that a DSSC can be successfully fabricated because of its low manufacturing cost and low harmful. It has wide applicability in renewable energy sectors.

Electrochemical and Mechanical Properties of Hexagonal Titanium Dioxide Nanotubes Formed by Sonoelectrochemical Anodization.

This study aimed to investigate the fabrication and characterization of hexagonal titanium dioxide nanotubes (hTNTs) compared to compact TiO2 layers, focusing on their structural, electrochemical, corrosion, and mechanical properties. The fabrication process involved the sonoelectrochemical anodization of titanium foil in various electrolytes to obtain titanium oxide layers with different morphologies. Scanning electron microscopy revealed the formation of well-ordered hexagonal TNTs with diagonals in the range of 30-95 nm and heights in the range of 3500-4000 nm (35,000-40,000 Å). The electrochemical measurements performed in 3.5% NaCl and Ringer's solution confirmed a more positive open-circuit potential, a lower impedance, a higher electrical conductivity, and a higher corrosion rate of hTNTs compared to the compact TiO2. The data revealed a major drop in the impedance modulus of hTNTs, with a diagonal of 46 ± 8 nm by 97% in 3.5% NaCl and 96% in Ringer's solution compared to the compact TiO2. Nanoindentation tests revealed that the mechanical properties of the hTNTs were influenced by their diagonal size, with decreasing hardness and Young's modulus observed with an increasing diagonal size of the hTNTs, accompanied by increased plastic deformation. Overall, these findings suggest that hTNTs exhibit promising structural and electrochemical properties, making them potential candidates for various applications, including biosensor platforms.

Characterization of modified titanium surfaces by anodisation and immersion tests

This paper explores the features of both nanoporous and compact TiO2 films formed by titanium anodisation in two experimental conditions, given that they have completely different morphologies and properties than those found by our previous studies. After anodisation, samples have been subjected for 20 days to immersion tests in different media (H2O, H3PO4, and KOH). Surface morphology, phase composition and wettability of anodised films were investigated using FESEM, FTIR, Raman spectroscopy, contact angle measurements and XPS, and the hydrophilicity of modified surfaces was investigated by immersion tests. Nanoporous films exhibited hydrophobic surfaces, but contact angle values gradually decreased after immersing films in H2O, H3PO4 and KOH media, respectively. However, compact films produced superhydrophilic surfaces, both before and after immersion tests, with the exception of immersing the film in a H3PO4 medium due to film removal by acid attack. As for compact films, an unusual morphology revealed by the presence of cone-shaped particles might be responsible for the adsorption of –OH groups arranged so as to favour anatase phase formation.

Readily Available Stable Nonquantum Dot CsPbBr3/TiO2 Heterostructure Crystals for Efficient Photocatalyst

The application of perovskites in the field of photocatalyst has been greatly limited due to their poor stability. Herein, the easy‐to‐prepare CsPbBr3/TiO2 heterostructure nanocrystals are employed as photocatalysts. The results confirm that the strong interfacial connection and efficient charge separation can be observed in CsPbBr3/TiO2 heterostructure crystals by natural crystal growth. Consequently, the generation of superoxide radicals, which is beneficial for the photocatalytic properties, is obviously increased. The CsPbBr3/TiO2 heterostructure nanocrystals completely degrade Rhodamine B in just 4 min. In addition, it is also found that the nonquantum dot CsPbBr3 crystals can be naturally encapsulated by the stable and compact TiO2 nanoparticles without complex synthesis process, which finally provides an excellent protection for the stability of CsPbBr3 perovskite. The CsPbBr3/TiO2 heterostructure nanocrystals can exhibit almost no degradation of photocatalytic performance exceeding 8 months in oceanic climate (10 °C ≤ T ≤ 32 °C, 20% ≤ RH ≤ 100%), showing a remarkable stability.

Single-source thermal deposition of (BA)2(MA)3Pb4I13 perovskite for a novel SnO2NRs/comp-TiO2@ irradiated-ITO based 2D/3D perovskite solar cell: Comparative study of irradiated ITO layer and its effect on device performance

Perovskite solar cells have achieved very good efficiency but their stability is still a big issue. To achieve an efficient a stable perovskite solar cell; a new simple single source thermal evaporation approach has been used to deposit 2D/3D (BA)2(MA)3Pb4I13 perovskite active layer, for realization of novel architecture of stable perovskite solar cell. Bi ions irradiated ITO electrode, coated with compact TiO2 and SnO2 nano-rods (NRs) layers, has been used as ETL. A unique approach is adopted to deliberately place SnO2 NRs horizontally on the surface comp-TiO2 coated irradiated ITO. Four, SnO2NRs/comp-TiO2@ irradiated-ITO based 2D/3D perovskite devices, have been fabricated with 1.2 GeV Bi ions irradiated ITO, at four different fluences (1.3 × 1011, 6.5 × 1011, 1.3 × 1012 and 2.6 × 1012 ions/cm2). Nano-hillocks formed by irradiation proved to contribute for the better performance to a certain point. It was found that the choice of using horizontally place SnO2-NRs in ETL contributed for better performance and stability of proposed device. Among four fabricated devices highest efficiency of 13.6 % is obtained for ITO irradiated with 1.3 × 1012 ions/cm2 fluence which is very encouraging for 2D/3D hybrid perovskite based solar cells in addition to improved performance all the devices showed good stability.

Effect of TiO2 structure on hysteretic behaviors in CH3NH3PbI3 perovskite solar cells

This work explores a mechanism behind hysteresis in CH3NH3PbI3 perovskite solar cells. The solar cells in this work employed either compact TiO2, mesoporous TiO2, or a combination of compact and mesoporous TiO2 as an electron transport layer. The solar cells using compact TiO2 layer displayed the most pronounced hysteresis compared to those which made use of mesoporous TiO2. Different hysteretic behavior is attributed to difference in the built-in electric fields present in the architecture of perovskite solar cell. The solar cells with a compact TiO2 layer have a built-in field which allows for iodide ions to migrate and accumulate near to the interface of indium-tin-oxide electrode, ultimately causing a reduction in the measured power conversion efficiency for forward bias scans. In case of the cells with a mesoporous TiO2 layer, they have the built-in fields configured in such a way that iodide ions are blocked from migrating on a large scale to the vicinity of the ITO electrode. This results in the reduced hysteresis in perovskite solar cells when a mesoporous TiO2 electron transport layer is employed.

Synergetic interfacial conductivity modulation dictating hysteresis evolution in perovskite solar cells under operation.

In this work, the configuration of compact TiO2 coating (c-TiO2) interface as electron transport layer (ETL) in giving rise to loss and gain of fill factor (FF) and therefore modulation of hysteresis behavior in perovskite solar cells (PSCs) is investigated. For this purpose, PSCs based on planar compact TiO2 (c-TiO2) as well as a scaffold-based architecture are studied. In the latter case c-TiO2 coats a hydrothermally grown titania nanorod scaffold. The results demonstrate that when c-TiO2 is used in planar configuration, FF considerably improves with prolonged light soaking which is in sharp contrast to what is observed for scaffold-based PSCs. Moreover, higher thickness of planar c-TiO2 is shown to be beneficial for sustaining FF in forward scan. Finally, through studying the intricate interfacial dynamics utilizing electrochemical impedance spectroscopy (EIS), it was concluded that for a PSC under operation, the cumulative effect of conductivity modulation at the perovskite with transport layer interfaces, for their respective charge carriers, determines the loss and gain in performance depending on scan rate, applied bias and prolonged light soaking. This work points towards multiple factors affecting PSC output, which could work either in confluence or against one another depending on the interfacial configuration of transport layers.

TiCl4 precursor affecting the performance of HTM-free carbon-based perovskite solar cell

The presence of TiO2 used as an efficient electron transport layer is crucial to achieving high-performance solar cells, especially for a hole transport material (HTM)-free carbon-based perovskite solar cell (PSC). The hydrolysis of TiCl4 is one of the most widely used routes for forming TiO2 layer in solar cells, which includes the stock solution preparation from TiCl4 initial precursor and the thermal hydrolysis of the stock solution. The second thermal hydrolysis step has been extensively studied, while the initial hydrolysis reaction in the first step is not receiving sufficient attention, especially for its influence on the photovoltaic performance of HTM-free carbon-based devices. In this study, the role of TiCl4 stock solution in the growth process of TiO2 layer is examined. Based on the analysis of the Ti(IV) intermediate states for different TiCl4 concentrations from Raman spectra, 2 M TiCl4 precursor exhibits moderate nucleation and growth kinetics without generating too many intermediates which occurs in 3 M TiCl4 precursor, yielding ∼300 nm size spherical TiO2 agglomerates with a rutile phase. In the aspect of devices, the HTM-free carbon-based PSCs fabricated using 2 M TiCl4 precursor deliver a conversion efficiency beyond 17%, which may be attributed to the reduced defect in compact TiO2 layer.

Simultaneous Enhancement of Efficiency and Operational-Stability of Mesoscopic Perovskite Solar Cells via Interfacial Toughening.

The combined effects of compact TiO2 (c-TiO2 ) electron-transport layer (ETL) are investigated without and with mesoscopic TiO2 (m-TiO2 ) on top, and without and with an iodine-terminated silane self-assembled monolayer (SAM), on the mechanical behavior, opto-electronic properties, photovoltaic (PV) performance, and operational-stability of solar cells based on metal-halide perovskites (MHPs). The interfacial toughness increases almost threefold in going from c-TiO2 without SAM to m-TiO2 with SAM. This is attributed to the synergistic effect of the m-TiO2 /MHP nanocomposite at the interface and the enhanced adhesion afforded by the iodine-terminated silane SAM. The combination of m-TiO2 and SAM also offers a significant beneficial effect on the photocarriers extraction at the ETL/MHP interface, resulting in perovskite solar cells (PSCs) with power-conversion efficiency (PCE) of over 24% and 20% for 0.1 and 1cm2 active areas, respectively. These PSCs also have exceptionally long operational-stability lives: extrapolated T80 (duration at 80% initial PCE retained) is ≈18000 and 10000h for 0.1 and 1cm2 active areas, respectively. Postmortem characterization and analyses of the operational-stability-tested PSCs are performed to elucidate the possible mechanisms responsible for the long operational-stability.

Exploring the impact of electron transport layer thickness and morphology on perovskite infiltration and photoresponse in HTM-free self-powered photodetector

Methylammonium lead Iodide (MAPbI3) is emerging as the frontrunner for high-performance photo-detection due to its superior optoelectronic characteristics and ease of processing. Titanium dioxide (TiO2) is the commonly employed electron transport layer in conventional perovskite-based photodetectors. However, the fundamental understanding of the role of TiO2 morphology and its thickness on the photodetector performance is yet to be explored explicitly. This work systematically investigates the impact of morphology (mesoporous versus compact TiO2 layer) and thickness of the TiO2 layer (50 nm – 3000 nm) on the MAPbI3 photodetector performance. The devices have been fabricated in a hole transport material (HTM)-free architecture with carbon as the top contact. The heterojunction between MAPbI3 and TiO2 renders the device with self-powered capability. The influence of the perovskite sensitisation in the TiO2 electrodes, carrier recombination characteristics and charge-carrier transfer resistances have been studied using photoluminescence and impedance spectroscopy. The TiO2 layer morphology and thickness affected the MAPbI3 infiltration and film formation kinetics. Impedance and photoluminescence spectroscopies reveal that TiO2 layers, with thickness above 460 nm, negatively affected the device performance. An optimum thickness of 460 nm-mesoporous TiO2 layer exhibited a superior responsivity and rise time of 2.9 A/W and 21 ms, respectively. The poor performance at higher thicknesses is due to the increased interfacial charge transfer resistance and charge carrier recombination. This work is the first report of extensive optimisation and study on the impact of TiO2 film morphology and thickness on the MAPbI3 photodetectors. The present work will be a key for modelling and designing high-performance perovskite photodetectors.

Impact of compact TiO2 interface modification on the crystallinity of perovskite solar cells

The effect of TiO2 interfacial morphology on perovskite crystallinity was investigated by modifying the micro and nanoscale surface roughness of compact TiO2. While surface treatments of the compact TiO2 layer are recognized as effective strategies to enhance the photovoltaic performance of perovskite solar cells, the discussion regarding the crystallinity of perovskite atop TiO2 has been limited. In this study, we explored the impact of micro and nano scale interface morphology on perovskite crystal formation and its subsequent effects on device performance. Surprisingly, despite the absence of noticeable voids at the interface between the compact TiO2 and perovskite layers, the perovskite crystal morphology exhibited significant improvement following either micro or nanoscale interfacial modification. This enhancement ultimately led to improved photoconversion efficiency and reduced I–V hysteresis. These results emphasize the importance of underlayer surface morphology in the perovskite crystallization and suggest that the presence of grain boundaries within the perovskite layer may also contribute to I–V hysteresis in perovskite solar cells.

Growth of Nanocolumnar TiO2 Bilayer by Direct Current Reactive Magnetron Sputtering in Glancing-Angle Deposition Configuration for High-Quality Electron Transport Layer.

The electron transport layer (ETL) plays a crucial role in solar cell technology, particularly in perovskite solar cells (PSCs), where nanostructured TiO2 films have been investigated as superior ETLs compared to compact TiO2. In this study, we explored the nanocolumnar growth of TiO2 in the anatase phase for bilayer thin films by DC reactive magnetron sputtering (MS) technique and glancing-angle deposition (GLAD). For the growth of the compact TiO2 layer, it was found that the crystalline quality of the films is strongly dependent on the sputtering power, and the samples deposited at 120 and 140 W are those with the best crystalline quality. However, for the nanocolumnar layer, the reactive atmosphere composition determined the best crystalline properties. By optimizing the growth parameters, the formation of TiO2 nanocolumns with a cross-sectional diameter ranging from 50 to 75 nm was achieved. The average thickness of the films exceeded 12.71 ± 0.5 µm. All nanostructured films were grown at a constant GLAD angle of 70°, and after deposition, the measured inclination angle of the nanocolumns is very close to this, having values between 68 and 80°. Furthermore, a correlation was observed between the quality of the initial layer and the enhanced growth of the TiO2 nanocolumns. All bilayer films are highly transparent, allowing light to pass through up to 90%, and present a band gap with values between 3.7 and 3.8 eV. This article offers the experimental parameters for the fabrication of a nanocolumnar TiO2 using the magnetron sputtering technique and the glancing-angle deposition configuration.

Realizing good combinations of strength-ductility and corrosion resistance in a Co-free Fe4Ni4Mn2CrTi high-entropy alloy via tailoring Ni/Ti-rich precipitates and heterogeneous structure

The development of alloys with good combinations of strength-ductility and corrosion resistance is a long-standing research theme for advanced materials engineering, which also holds true for the newly emerged high-entropy alloys (HEAs). Here, Ni/Ti-rich precipitates and heterogeneous structure were introduced for the primary purpose of improving strength-plasticity synergy of a Co-free Fe4Ni4Mn2CrTi HEA with good anti-corrosion performance. Specifically, four typical states of this HEA were tailored and compared, including i) as-cast, ii) homogenized, iii) post deformation annealing (PDA) sample with heterogeneous structure and iv) PDA sample with homogeneous structure. The structural features, mechanical properties, and underlying phase transformation mechanisms were systematically investigated. Phase transformation of η-D024 to γ′-L12 was realized during annealing treatments, based on the intrinsic stacking faults formed by repeating removal of the (0001) planes in the η structure. Compared with the homogenized counterpart, the strength-ductility synergy was achieved in the alloy iv, showing an evident increment of ∼43.4% in yield strength (σ0.2) and ∼57.8% in ultimate tensile strength (σUTS), respectively, resulting from solid-solution strengthening, grain-boundary strengthening and precipitation strengthening, yet without sacrificing ductility. Good combinations of strength and ductility were also achieved in the alloy iii with heterogeneous structure, possessing an even higher σ0.2 and σUTS yet maintaining a moderate elongation, whose strength contribution from hetero-deformation induced hardening is recognized as a significant strengthening mechanism. Additionally, in comparison with the conventional corrosion-resistant 304 stainless steel, compact TiO2 and Cr2O3 in the passive film give rise to more superior anti-corrosion properties of the homogenized HEA. This paper provides a new paradigm in the controllable design of novel low-cost high-performance HEAs for achieving their potential structural and functional engineering applications.

Performance Improvement of Dye-Sensitized Solar Cells with Pressed TiO2 Nanoparticles Layer

A simple and low-cost fabrication method of dye-sensitized solar cells (DSSCs) was developed to improve the structure and performance of the photoanode with the pressed layer and compact TiO2 thin film using spin coating, screen printing, and mechanical compression. In this study, four different TiO2 layers were adopted to fabricate photoanodes: a mesoporous TiO2 nanoparticles (NPs) layer, a pressed TiO2 NPs layer, a mesoporous TiO2 NPs layer on the TiO2 compact thin film, and a pressed TiO2 NPs layer on the TiO2 compact thin film. The compact thin film was deposited on the fluorine-doped tin oxide (FTO) glass via spin coating, while the mesoporous TiO2 NPs layer was deposited via the screen-printing method. The pressed TiO2 NPs layer was produced by compressing the mesoporous TiO2 NPs layer with a hydraulic press machine. When using the pressed TiO2 NPs layer for the photoanode of DSSC, the power conversion efficiency of DSSC was enhanced the most. The electron lifetime for DSSC with photoanodes based on the pressed TiO2 NPs and mesoporous TiO2 NPs layers were 8.217 and 6.287 ms, respectively. The power conversion efficiency of DSSC with photoanodes based on the pressed TiO2 NPs layer was 5.4%, while that based on the mesoporous TiO2 NPs layer was 4.08%. DSSC with photoanodes based on the pressed TiO2 NPs layer showed a significant increase in the power conversion efficiency by 36.16% compared to that based on the mesoporous TiO2 NPs layer.

Compact TiO2 layer by UV-assisted TiBr4 chemical bath deposition for perovskite solar cells

A new method to prepare a compact TiO2 layer for perovskite solar cells is introduced. The method features a UV-assisted chemical bath in an aqueous TiBr4 solution. The process does not require sophisticated systems to implement making scaling-up easy and the precursor ensures a uniform TiO2 layer with densely-packed planar grains. UV light provides an alternative to the temperature-assisted CBD process and eliminates the necessity to stir the solution during a deposition that opens new horizons for further scaling up PSCs. The new compact layer was compared to the spin-coated TiO2 layer and it was found that the novel method allows obtaining a more uniform layer with conformal coverage of the substrate. The new TiO2 layer was tested for perovskite solar cells and showed an improvement in open-circuit voltage (VOC) which can be explained by improved morphology and surface coverage of the TiO2 layer.

Improved corrosion and adhesion properties of titanium alloy for endoprostheses applications using a two-step anodization method

To promote adherence, hydrophilicity and corrosion properties, TiO2 nanotubes, compact TiO2 films and a combination of them were formed on Ti6Al4V alloy using only electrochemical methods. Nanostructured arrays being largely studied, the work was focused on the compact layer and the effect of the additional anodization. Corrosion results in physiological conditions were supported by surface and cross-section observations to choose the best protective treatment. Contact angles were measured to have an idea of osseointegration properties. The ageing of the surface reducing the hydrophilicity, two activation treatments were proposed to recover the good initial values. Finally, interfacial adhesion was evaluated by tensile tests. Corrosion and adhesion properties of the nanotube layer (ipass: 16 μA·cm−2, pull-out surface: 100 %) can be significantly improved by the second anodization (ipass: 0,12 μA·cm−2, pull-out surface: 0 %) that seals the bottom of the tube by an underneath compact oxide layer, preserving their hydrophilicity property.