Search Results (431)

Titanium dioxide nanotubes (TNTs) have favorable biocompatibility and nanoscale morphologies, and they have been extensively explored for titanium implant surface modifications. However, they are limited by their mechanical strength and weak interfacial adhesion between the nanotube layer and the titanium substrate. This restricts their clinical applications. In this study, a two-step electrochemical anodization method is developed to achieve in situ tantalum (Ta) doping into TNT arrays to enhance their mechanical performance without altering their nanotubular structure. The surface morphology, element and crystal phase composition, surface roughness, wettability, and mechanical properties of the Ta-doped TNTs were then thoroughly characterized. Scanning electron microscopy revealed that the Ta doping did not change the nanotube architecture. In addition, X-ray diffraction confirmed anatase TiO₂ formation in all the samples. X-ray photoelectron spectroscopy demonstrated that Ta⁵⁺ doping significantly reduced oxygen vacancies, and this was a concentration-dependent effect. Nanoindentation and scratch tests showed that the hardness, the Young’s modulus of the nanotube layer, and the adhesion strength between the nanotubes and the titanium substrate were markedly improved compared to those of the undoped TNTs. These mechanical enhancements may be attributed to lattice densification due to Ta doping. In vitro cell assays further demonstrated that the Ta-TNTs promoted rat bone marrow mesenchymal stem cell adhesion, proliferation, and osteogenic differentiation. This was evidenced by increased alkaline phosphatase activity, enhanced mineralization, and upregulated gene expression levels. The results suggest that the Ta-doped TNTs offer a pathway for the development of mechanically robust and bioactive implant surfaces for dental and orthopedic applications. Full article

Direct borohydride fuel cells (DBFCs) are emerging as a promising source of clean energy; however, their performance depends heavily on efficient anode catalysts for the oxidation reaction of sodium borohydride (BOR). In this study, we developed and tested the Au–NiZn/Ti electrocatalyst designed to improve the performance of DBFCs. Electrodeposition and alkaline leaching were utilized to transform a zinc-rich nickel coating into a porous dendritic structure on a titanium substrate. By adding a small amount of gold crystallites through galvanic displacement, the surface roughness and the number of active sites available for the reaction were significantly increased. Electrochemical tests confirmed that this modification enhances BOR and effectively suppresses unwanted side reactions like hydrogen evolution. The resulting catalyst demonstrated high stability, maintaining over 88% of its current density during extended operation. Ultimately, the study positions this gold-modified material as a cost-effective and durable solution for clean energy conversion technologies. Full article

Superconducting transition-edge sensors (TESs) exhibit excellent single-photon detection performance. The quantum efficiency (QE), which quantifies the probability that an incident photon is absorbed and converted into a measurable signal, is strongly governed by the optical properties of the constituent thin films. Specifically, for typical TES device architectures where optical transmission is negligible, maximizing the QE requires the minimization of surface reflectance to ensure high photon absorptance. In this work, we systematically study how anodic oxidation modifies the optical response of superconducting titanium (Ti) thin films that are relevant for TES devices. Anodization is carried out under well-controlled constant-current conditions in an aqueous electrolyte containing ammonium pentaborate and ethylene glycol. Experimentally, we show that anodic oxidation substantially reduces the ultraviolet (UV) reflectance and induces a monotonic redshift of the reflectance minimum as the anodic oxidation cutoff voltage (V_ocv) increases. Finite-difference time-domain (FDTD) simulations based on spectroscopic ellipsometry data reproduce the measured spectra with good fidelity for most samples, validating the extracted optical constants. By comparing samples prepared at different current densities and oxidation times, we identified V_ocv as the primary parameter controlling the reflectance response, because it determines the thickness and effective optical properties of the anodic TiO_x layer. Under optimized conditions, reflectance values below 1% in the 320.9–340.2 nm wavelength range and below 2% in the 316.3–346.3 nm range are achieved, indicating a significant enhancement in potential absorptance. These results demonstrate that anodic oxidation provides a simple, post-fabrication, and voltage-tunable route for engineering the UV optical response of Ti-based TES structures and for enhancing their potential QE by suppressing reflection losses. Full article

Titanium-based implants are widely used in orthopedic and trauma surgery; however, postoperative infections remain a major cause of implant failure due to early bacterial adhesion. Localized antibiotic delivery from surface coatings offers a promising strategy to prevent initial colonization during the critical postoperative period. In this study, a self-organized TiO₂ nanotubular oxide layer was fabricated on Ti-407 by electrochemical anodization in a glycerol/NH₄F electrolyte at 40–60 V. SEM revealed vertically aligned single-walled nanotubes with diameters and lengths of ~80 nm and ~10 µm respectively. XPS analysis verified TiO₂ formation with Al–O, V–O, and fluorine incorporation. Ceftriaxone was successfully loaded into the nanotubular structure, as identified by FT-IR. UV–Vis measurements showed a biphasic release profile consisting of an initial burst followed by sustained release determined by nanotube geometry. In vitro antibacterial activity was evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli using optical density, CFU quantification, and an agar diffusion assay. Unloaded surfaces showed no inhibition, whereas ceftriaxone-loaded nanotubes significantly reduced bacterial growth up to ~6% and generated clear inhibition zones. These findings demonstrate, for the first time, that TiO₂ nanotubular coatings derived from Ti-407 support drug loading and demonstrate effective in vitro antibacterial activity, highlighting their potential for infection-resistant orthopedic implants. Full article

Traditional methods for preparing rare-earth-doped TiO₂ nanotubes are multi-step and often result in uneven dopant distribution, while pure TiO₂ is limited by its wide bandgap and rapid charge recombination. In this study, a one-step in situ synchronous anodization strategy is developed to fabricate gadolinium (Gd)-doped TiO₂ nanotube arrays directly on a titanium substrate. By adding gadolinium nitrate to an ethylene glycol–NH₄F electrolyte, Gd incorporation and nanotube growth are achieved simultaneously, reducing the processing steps by over 60%. The obtained Gd–TiO₂ nanotubes exhibit extended visible-light absorption with an edge beyond 500 nm and show a methylene blue degradation efficiency of 90% within 60 min, which is 50% higher than that of undoped TiO₂. Scavenger experiments reveal that ·OH radicals play the predominant role in the photocatalytic process. First-principles calculations further confirm significant bandgap narrowing from 2.89 eV to 2.46 eV after Gd doping. This work provides a simple, efficient, and scalable synthesis route for high-performance TiO₂-based photocatalysts with enhanced solar-driven activity. Full article

The plasma-catalytic conversion of CO₂ is a promising route toward sustainable fuel and chemical production under mild operating conditions. However, many aspects still need to be better understood to improve performance and better understand the catalyst-plasma synergies. Among them, one aspect concerns understanding whether photons emitted by plasma discharges could induce changes in the catalyst, thereby promoting interaction between plasma species and the catalyst. This question was addressed by investigating the CO₂ splitting reaction in a planar dielectric barrier discharge (pDBD) reactor using titania-based catalysts that simultaneously act as discharge electrodes. Four systems were examined feeding pure CO₂ at different flow rates and applied voltage: bare titanium gauze, anodically formed TiO₂ nanotubes (TiNT), TiNT decorated with Ag–Au nanoparticles (TiNTAgAu), and TiNT supporting Ag–Au nanoparticles coated with polyaniline (TiNTAgAu/PANI). The TiNTAgAu exhibited the highest CO₂ conversion (35% at 10 mL min⁻¹ and 5.45 kV) and the most intense optical emission, even in the absence of external light irradiation, suggesting that the improvement is primarily attributed to plasma–nanoparticle interactions and self-induced localized surface plasmon resonance (si-LSPR) rather than conventional photocatalytic pathways. SEM analyses indicated severe plasma-induced degradation of TiNT and TiNTAgAu surfaces, leading to performance decay over time. In contrast, the TiNTAgAu/PANI catalyst retained structural integrity, with the polymeric coating mitigating plasma etching while maintaining competitive efficiency. There is thus a complex behavior with catalytic performance governed by nanostructure stability, plasmonic enhancement, and the interfacial protection. The results demonstrate how integrating plasmonic nanoparticles and conductive polymers can enable the rational design of durable and efficient plasma-photocatalysts for CO₂ valorization and other plasma-assisted catalytic processes. Full article

Background: Soft tissue stability around dental implant abutments is critical for maintaining a functional peri-implant seal. Yellow anodization is used to improve the aesthetic and surface characteristics of titanium abutments, yet its epithelial effects under more physiologically relevant 3D conditions remain insufficiently explored. Objective: To develop a 3D bioprinted in vitro peri-implant mucosa model and to compare epithelial cell responses on yellow anodized versus turned titanium abutment surfaces. Methods: Commercial Grade 5 (Ti6Al4V) titanium abutments were anodized and compared with turned controls. A collagen-based 3D bioprinted “collar-like” construct incorporating YD-38 epithelial cells was fabricated using a custom holder system to simulate peri-implant mucosal contact. Samples were cultured for 14 and 21 days. Cell distribution and morphology were assessed by optical microscopy and HE staining, while cytoskeletal organization was evaluated by TRITC-phalloidin/Hoechst staining and confocal microscopy. Quantitative fluorescence analysis was performed at 21 days. Results: Both surfaces supported epithelial coverage in the 3D environment. Anodized specimens showed more pronounced actin cytoskeletal organization and the presence of actin-rich, filamentous cellular extensions compared with turned controls. Quantitative image analysis demonstrated significantly higher TRITC-phalloidin signal intensity at 21 days on anodized samples (p < 0.001). Conclusions: Within the limitations of a 3D epithelial in vitro model using YD-38 cells, yellow anodization was associated with enhanced epithelial cytoskeletal organization compared with turned titanium. The presented 3D bioprinted platform may serve as a practical in vitro tool for screening abutment surface modifications relevant to peri-implant soft tissue integration. Full article

Y-branched TiO₂ nanotubes (NTs) were produced by anodizing titanium plates derived from aerospace production leftovers and subsequently engineered to develop an enhanced TiO₂-based photocatalytic system. The NTs were electrochemically reduced to obtain reduced TiO₂ nanotubes (rTN) with a narrowed bandgap, followed by surface modification with polydopamine (PD) and silk fibroin-derived quantum dots (QDs) to promote enhanced UV and visible-light photocatalysis for wastewater treatment. The QDs were hydrothermally synthesized from Bombyx mori silk fibroin. Scanning Electron Microscopy (SEM) revealed spherical QD agglomerates encapsulated within the PD layer, while Energy Dispersive X-ray Spectroscopy (EDX) confirmed the presence of carbon and nitrogen originating from both PD and QD. The resulting rNT/PD/QD photocatalyst exhibited a significantly reduced bandgap (1.03 eV), increased Urbach energy (1.35 eV), and moderate hydrophilicity. A high double-layer capacitance (C_dl) indicated an enlarged electrochemically active surface due to the combination of treatments. Electrochemical characterization demonstrated reduced electrical resistance, higher charge density, and lower electron–hole recombination, leading to improved interfacial charge transfer efficiency and electrochemical stability during multi-cycle cyclic voltammetry measurements. Preliminary photocatalytic tests show that the rNT/PD/QD photocatalyst achieved a degradation efficiency of 79.26% for methyl orange (MO) and 35% for tetracycline (TC). Full article

Recent studies show that titanium (Ti)-based alloys combine established mechanical strength, corrosion resistance, and biocompatibility with emerging electrical and electrochemical properties relevant to bioelectronics. The main goal of the present manuscript is to give a wide-ranging overview on the use of Ti-alloys in electronics and biomedicine, focusing on a comprehensive analysis and synthesis of the existing literature to identify gaps and future directions. Concurrently, the identification of possible correlations between the effects of the manufacturing process, alloying elements, and other degrees of freedom influencing the material characteristics are put in evidence, aiming to establish a global view on efficient interdisciplinary efforts to realize high-added-value smart devices useful in the field of biomedicine, such as, for example, implantable apparatuses. This review mostly summarizes advances in surface modification approaches—including anodization, conductive coatings, and nanostructuring that improve conductivity while maintaining biological compatibility. Trends in applications demonstrate how these alloys support smart implants, biosensors, and neural interfaces by enabling reliable signal transmission and long-term integration with tissue. Key challenges remain in balancing electrical performance with biological response and in scaling laboratory modifications for clinical use. Perspectives for future work include optimizing alloy composition, refining surface treatments, and developing multifunctional designs that integrate mechanical, biological, and electronic requirements. Together, these directions highlight the potential of titanium alloys to serve as foundational materials for next-generation bioelectronic medical technologies. Full article

Postoperative infections in orthopedic implants remain a major complication, particularly in open fractures, where early bacterial colonization and the limited bioactivity of titanium alloys hinder osseointegration. This study reports a hierarchical coating synthesized in situ on Ti-407 alloy, integrating bioactive and antibacterial functions. TiO₂ nanotube arrays were formed by anodization and subsequently functionalized by sequential electrodeposition of Ag nanoparticles and doped hydroxyapatite (HA) (Ca, P, Mg, Zn). SEM/EDS confirmed uniform coatings with a Ca/P ratio near stoichiometric HA (1.61). Agar diffusion assays against E. coli ATCC® 25922™ revealed well-defined inhibition zones, confirming the antibacterial efficacy of the coatings. These findings highlight the potential of hierarchical coatings to enhance bone integration while reducing infection risk in orthopedic implants. Full article

Many special structures such as pipeline, revolving gears, and tanks suffer from biofouling used in marine environment, which could induce serious results in the ship system such as blockage and stuck, consequently lead to failure of the mechanical system and power system. Generally, coatings with antifouling agents are used for protecting metal structures from biofouling, but coatings are not conveniently applicable in the high velocity flowing seawater and narrow space. Electrochlorination and electrolysis of copper and aluminum anode are usually used in these circumstances, but the electric power will lead to stray current corrosion to the component. For the sake of convenience and safety, Cu-Ti pseudo alloy antifouling anode was proposed in this work for antifouling in pipeline and other narrow spaces without external electric power. Four Cu-Ti pseudo alloy antifouling anodes with different Ti contents (mass fraction) of 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% were investigated with computational method, and a 15 wt.% Ti content Cu-Ti pseudo alloy antifouling anode was prepared by cold spray, and the microstructure and composition of the anode were observed by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Electrochemical tests were conducted to obtain the corrosion potential, potentiodynamic polarization curve, and micro zone electrochemical information in natural seawater, and the Cu ions releasing behavior were analyzed using inductively coupled plasma (ICP). The results indicated that in natural seawater, copper particles, and titanium particles on the surface of anode samples can form micro galvanic couples. With the increase in Ti mass fraction, the number of micro primary cells composed of copper particles and titanium particles increases, and the corrosion rate of Cu particles increased. When the Ti mass fraction is 15%, the corrosion rate is the fastest, and the copper ion release rate increases by nearly ten times, reaching 147 μg/(cm²·d). This method can effectively accelerate the releasing rate of Cu ions in Cu-Ti pseudo alloy anode and promote the antifouling effect. Full article

Electrolysis and biological processes, such as fermentation and microbial electrolysis cells, offer efficient hydrogen production alongside wastewater treatment. This study presents a novel microbial electrolyzer (ME) comprising a titanium dioxide (TiO₂) anode, a nickel–iron–carbon (NiFeC) cathode, and a cellulose nanocrystal proton exchange membrane (CNC-PEM) designed to generate hydrogen from palm oil mill effluent (POME). The system is powered by a 12 V electric double-layer organic supercapacitor (EDLOSC) integrated with a ZnO/PVA-based solar thin film. Power delivery to the TiO₂-NiFeC-PEM electrolyzer is optimized using an Adaptive Neuro-Fuzzy Inference System (ANFIS). Laboratory-scale pilot tests demonstrated effective degradation of POME’s organic content, achieving a hydrogen yield of approximately 60%. Additionally, the nano-structured ZnO/CuO–ZnO/PVA solar film facilitated stable power supply, enhancing in situ hydrogen production. These results highlight the potential of the EDLOSC-encased ZnO/PVA-powered electrolyzer as a sustainable solution for hydrogen generation and industrial wastewater treatment. Full article

This work reports on the effects of surface pre-treatment and EPD process parameters on the nanomechanical and adhesive performance of chitosan-based composite coatings fabricated on a Ti13Zr13Nb alloy. Three different coating systems were prepared: chitosan–Cu (series A), chitosan–HAp (series B), and HAp–Cu (series C). Coatings were deposited from suspensions at different voltages (10–30 V) and for various times (1–2 min) onto polished, anodized, and laser surface-treated titanium alloy substrates. Microstructural, nanomechanical, and adhesion properties were characterized by means of SEM, nanoindentation, and nanoscratch testing, respectively. Chitosan–Cu coatings exhibited the highest hardness (up to 8.2 GPa) and stiffness due to the homogeneous dispersion of Cu nanoparticles and strong interfacial bonding to the underlying anodized TiO₂ layer. Chitosan–HAp coatings were softer (0.05–0.13 GPa) and highly plastic, particularly after laser surface treatment due to their specific porous, polymer-dominated structure. HAp–Cu coatings exhibited an intermediate mechanical behavior with a hardness between 0.1 GPa and 2.9 GPa and enhanced elastic recovery (Wp/We ≈ 3.5–4.7), particularly for anodized substrates. The nanoscratch test results showed that the HAp–Cu coatings exhibited the highest adhesion Lc (≈150–173 mN), confirming a synergistic effect of hybrid composition and heat treatment on interfacial toughness. The present data demonstrate that the optimization of anodizing and EPD processing parameters allows for the manipulation of the mechanical integrity and adhesion of bioactive chitosan-based coatings for titanium biomedical applications. Full article

Commercially pure (CP) titanium is widely used for long-term biomedical implants due to its high biocompatibility and corrosion resistance. However, its relatively low strength limits its use in highly loaded applications. Ultrafine-grained (UFG) titanium obtained through severe plastic deformation offers enhanced mechanical performance while maintaining the stability of CP titanium. This study investigates how electrochemical surface modification by anodization affects the corrosion, biological performance, and technological behavior of UFG titanium. TiO₂ layers with nanotubular and nanoporous morphologies were produced at anodization voltages between 20 and 60 V. Corrosion tests in physiological solution confirmed stable passive behavior with corrosion rates below 4 µm year⁻¹, and surface wettability increased markedly with anodization. Osteoblast-like MG-63 cells exhibited good viability on all anodized surfaces, with improved adhesion and proliferation on samples anodized at 60 V. The porous TiO₂ layers were successfully intercalated with dimethyl sulfoxide and ibuprofen, demonstrating potential for local drug delivery. Implantation simulations on real Nanoimplant^® prototypes confirmed sufficient mechanical stability of the anodized layer. Overall, the optimized anodization of UFG titanium enhances its biological response while maintaining corrosion resistance, supporting its clinical use in long-term dental and orthopedic implants with integrated drug-release functionality. Full article

Aluminum anodizing has been a well-established method of corrosion protection for over a century. A nanoporous and hexagonally arranged anodic aluminum oxide has become one of the most important template materials in nanotechnology. A totally new branch of research in anodizing was sparked by purple gold anodizing. This pioneering research showed that metal aluminides can be anodized and result in new classes of nanomaterials. Simultaneously, materials from Ti-Al systems were anodized, and the transition from nanopores to the nanotubes was mechanistically understood. Also, materials like Ni₃Al were anodized; however, the most frequently used aluminides are materials from the Fe-Al binary phase diagram, from Fe₃Al to FeAl₃. The research on metal aluminides has shown that it is possible to obtain mixed oxides with a highly developed nanostructured morphology. A significant amount of fundamental research has shown it is possible to obtain such mixed oxides with tunable band gaps, depending on the substrate material, anodizing conditions, and heat treatment. Despite significant progress in fundamental research, there is a noticeable lack of applied research on this class of materials. Full article