Electrochemical Surface Biofunctionalization of Titanium through Growth of TiO2 Nanotubes and Deposition of Zn Doped Hydroxyapatite

The current research aim is to biofunctionalize pure titanium (Ti, grade IV) substrate with titania nanotubes and Zn doped hydroxyapatite-based coatings by applying a duplex electrochemical treatment, and to evaluate the influence of Zn content on the physico-chemical properties of hydroxyapatite (HAp). The obtained nanostructured surfaces were covered with HAp-based coatings doped with Zn in different concentrations by electrochemical deposition in pulsed galvanostatic mode. The obtained surfaces were characterized in terms of morphology, elemental and phasic composition, chemical bonds, roughness, and adhesion. The nanostructured surface consisted of titania nanotubes (NT), aligned, vertically oriented, and hollow, with an inner diameter of ~70 nm. X-Ray Diffraction (XRD) analysis showed that the nanostructured surface consists of an anatase phase and some rutile peaks as a secondary phase. The morphology of all coatings consisted of ribbon like-crystals, and by increasing the Zn content the coating became denser due to the decrement of the crystals’ dimensions. The elemental and phase compositions evidenced that HAp was successfully doped with Zn through the pulsed galvanostatic method on the Ti nanostructured surfaces. Fourier Transform Infrared spectroscopy (FTIR) and XRD analysis confirmed the presence of HAp in all coatings, while the adhesion test showed that the addition of a high quantity leads to some delamination. Based on the obtained results, it can be said that the addition of Zn enhances the properties of HAp, and through proper experimental design, the concentration of Zn can be modulated to achieve coatings with tunable features.

Characterization of Titanium-Based Films Deposited by DC Sputtering Reactive on AISI 1018 Steel

The coated surfaces first layer Ti and second layer TiO2 as coating Nanostructured thin films of using DC sputtering on structural steel (AISI l018) and study characterization of coating SEM/EDS inspection shown a clearly perfect incorporation of layer by dc sputtering a granular structure of the layer with a variable hemisphere’s forms varied from 33 to 46 nm in size. X-XRD test complete for specimen indicates was found anatase phase titanium dioxide, the resulted coating layer of the target of Ti powders gives different morphology from the Ti layer alone The Specimens roughness average of coated Ti and TiO2with respectively was 4.831nm, 7.93 nm. Found that titanium layer will show a major part in increasing the bonding with improving the bond between the substrate steel AISI (1018) and the titanium oxide layer. The Vickers hardness increases when the coating with a layer of titanium with an oxygen content of ceramic layer is formed from 192.3 HV to 227 for Ti as well as important increase was detected in the Tio2 coating to 240 HV. In addition, Ti and Tio2 thin layer considered as a good barrier for hydrogen permeation through steel structure especially at cathode protection in pipelines.

Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst

In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption, and photoluminescence (PL) spectroscopy. A possible photocatalytic mechanism was also proposed. XRD patterns revealed the anatase phase of TiO2 and Lac-TiO2 samples. High-magnification FE-SEM images showed that the TiO2 and Lac-TiO2 samples exhibited spherical-like structures. XPS results complementarily confirmed the presence of Ti, O, and C as the main elements of the Lac-TiO2 samples. Interestingly, the DRS spectra of the Lac-TiO2 samples extended into the visible region. FTIR spectra presented the characteristic bands of TiO2 and hydroxyl groups on the TiO2 surface. Instead of hydroxyl groups, the characteristic bands of laccaic acid were observed on the surface of the Lac-TiO2 samples. The photocatalytic properties of the Lac-TiO2 samples were evaluated in terms of methyl orange degradation under visible light irradiation. The Lac-TiO2 samples showed higher photocatalytic performance than the TiO2 sample.

Laser-Induced Chemical Liquid-Phase Deposition Plasmonic Gold Nanoparticles on Porous TiO2 Film with Great Photoelectrochemical Performance

This paper considers the photoelectrochemical characteristics of a composite porous TiO2 thin film with deposited plasmonic gold nanoparticles. The deposition of gold nanoparticles was carried out by the laser-induced chemical liquid-phase deposition (LCLD) method. The structural characteristics of the composite have been studied; it has been shown that the porous TiO2 film has a lattice related to the tetragonal system and is in the anatase phase. Gold nanoparticles form on the surface of a porous TiO2 film. A complex of photoelectrochemical measurements was carried out. It was shown that the deposition of plasmonic gold nanoparticles led to a significant increase in the photocurrent density by ~820%. The proposed concept is aimed at testing the method of forming a uniform layer of plasmonic gold nanoparticles on a porous TiO2 film, studying their photocatalytic properties for further scaling, and obtaining large area Au/TiO2/FTO photoelectrodes, including in the roll-to-roll process.

Synthesis and Characterization of High Surface Area Nano Titanium Dioxide

TiO2 and TiO2-Al2O3 nanoparticles were synthesized via sol-gel method using hydrolysis of Titanium tetraisopropoxide (TTIP) with ethanol and water mixture as titania source. TiO2-Al2O3 Nano-composite was successfully synthesized using the sol-gel technique. Tetraisopropoxide and aluminium isopropoxide were used to prepare TiO2-Al2O3. All prepared samples calcination were conducted at different temperature (400 to 700) oC. The synthesized TiO2 and TiO2-Al2O3 nanocomposites were then characterized by XRD, AFM, BET surface area, SEM, XRF. XRD, the analysis showed that the presence of alumina (Al2O3) in the TiO2 has an effect on crystal size, particles size, surface area, and crystal phases; The XRD result revealed that the prepared TiO2 nanoparticles were anatase phase at 400oC, and 500oC, and transformed to rutile from 600oC to 700oC, but after addition of alumina TiO2 was of anatase phase, without any rutile at all calcination temperatures, also, the addition of alumina leads to a significant decrease in the crystal size, particles size, especially at high temperatures while the surface area of pure titanium was increased, and this corresponds to the results of the AFM and SEM. The best-obtained surface area was 355.18 m2/ gm. with 34.98 nm of average particle size at 500oC in comparison with pure nano titanium dioxide

Synthesis of Ag decorated TiO2 nanoneedles for photocatalytic degradation of methylene blue dye

Water pollution due to the discharge of industrial effluents such as dyes is a serious concern that requires a potential remedy. In this context, photocatalysis is a potent and ecofriendly strategy to degrade these toxic water effluents. In this study, a novel approach to prepare TiO2 nanoneedles decorated with Ag nanoparticles is reported. The sample was prepared using modified photodeposition and was annealed at 400 °C. The X-ray diffraction (XRD) revealed that TiO2 in anatase phase with the presence of Ag were prepared successfully. The corresponding crystalline size of TiO2 and Ag were 6.86 nm and 3.94 nm, respectively. The scanning electron microscopy (SEM) showed that the prepared TiO2 exhibited nanoneedles structure decorated with Ag nanoparticles. The prepared sample exhibited impressive photocatalytic performance toward degrading of 50 ppm Methyl Blue (MB) in the presence of UV irradiation. Using catalyst dose of 4 mg the photodegradation efficiency (PDE) reached to 98.7% after 50 min of UV irradiation. This improved photocatalytic activity is attributed to high catalytic activity and surface area of the synthesized Ag decorated TiO2 nanoneedles.

Structural, Physical, and Mechanical Analysis of ZnO and TiO2 Nanoparticle-Reinforced Self-Adhesive Coating Restorative Material

This study aimed to modify an EQUIA coat (EC; GC, Japan) by incorporating 1 and 2 wt.% of zinc oxide (ZnO; EC-Z1 and EC-Z2) and titanium dioxide (TiO2; EC-T1 and EC-T2) nanoparticles, whereby structural and phase analyses were assessed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. Thermogravimetric analysis/differential scanning calorimetry, micro-hardness, and water absorption analyses were conducted, and the microstructure was studied by scanning electron microscopy/energy-dispersive spectroscopy. FTIR spectra showed a reduction in peak heights of amide (1521 cm−1) and carbonyl (1716 cm−1) groups. XRD showed peaks of ZnO (2θ~31.3°, 34.0°, 35.8°, 47.1°, 56.2°, 62.5°, 67.6°, and 68.7°) and TiO2 (2θ~25.3°, 37.8°, 47.9, 54.5°, 62.8°, 69.5°, and 75.1°) corresponding to a hexagonal phase with a wurtzite structure and an anatase phase, respectively. Thermal stability was improved in newly modified materials in comparison to the control group. The sequence of obtained glass transitions was EC-T2 (111 °C), EC-T1 (102 °C), EC-Z2 (98 °C), EC-Z1 (92 °C), and EC-C (90 °C). EC-T2 and EC-T1 showed the highest (43.76 ± 2.78) and lowest (29.58 ± 3.2) micro-hardness values. EC showed the maximum water absorption (1.6%) at day 7 followed by EC-T1 (0.82%) and EC-Z1 (0.61%). These results suggest that EC with ZnO and TiO2 nanoparticles has the potential to be used clinically as a coating material.

Annealing Temperature Influences the Cytocompatibility, Bactericidal and Bioactive Properties of Green Synthesised TiO2 Nanocomposites from Calotropis Gigantea

Annealing is a crucial functional parameter relevant to the green synthesis and bactericidal properties of TiO2 nanocomposites (TiO2-NPs). In this work, the effect of the annealing temperature on the physicochemical and bactericidal properties of TiO2-NPs obtained from Calotropis gigantea was comprehensively studied. The synthesised TiO2-NPs were characterised using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, UV–Vis spectrophotometer and FTIR spectroscopy. The bactericidal properties were determined via the minimum inhibitory concentration (MIC) and Kirby–Bauer disc diffusion methods. The cytocompatibility of green TiO2 was further investigated using fibroblast cells lines model. Results indicated that amorphous-phase TiO2-NPs were transformed into the anatase phase at 500 °C with a crystallite size of 40.9 nm and MIC of 100 mg/mL towards S. aureus (colony count reduction from 4.3 log10 to 1.01 log10). Whereas TiO2-NPs annealed at 400 °C demonstrated no bacterial reduction, TiO2-NPs annealed at 500 °C showed a moderate zone of inhibition of 6.33–6.83 mm towards Escherichia coli and Pseudomonas aeruginosa. Findings from this study found that TiO-500C nanocomposites concentration at 100 mg/mL is cytocompatible to the fibroblast cells lines with proliferation rate/activity higher than 116% after 24 h treatment. The plant-mediated nano-sized cubic and spherical anatase TiO2-NPs encapsulated bioactive green elements, such as carbon, sodium, magnesium, chlorine, potassium, calcium and sulphur, from the C. gigantea extract, ultimately leading to versatile and eco-friendly bactericidal agents with wound-healing properties. Further studies are necessary to support the findings of this work.

On the incorporation of nano TiO2 to inhibit concrete deterioration in the marine environment

To develop high deterioration resistance concrete for marine infrastructures, two types of nano TiO2 (NT) including anatase phase NT and silica surface-treated rutile phase NT were incorporated into concrete. The fabricated NT modified concrete was then put into the marine environment for 21 months in this study. The effects and mechanisms of two types of NT on the deterioration of concrete in the marine environment were investigated from three aspects, including seawater physical and biological and chemical actions on concrete with NT. Under the seawater physical action, the exposed degree of coarse sand particles on the surface of control concrete is greater than that of concrete with NT. Owing to the microorganism biodegradation property of NT, the elimination and inhibition rates of concrete with NT on microorganisms can reach up to 76.98% and 96.81%, respectively. In addition, the surface biofilm thickness of concrete can be reduced by 49.13% due to the inclusion of NT. In the aspect of seawater chemical action, NT can increase the pH value inside concrete by 0.81, increase the degree of polymerization of C-S-H gel, and improve the interfacial transition zone between cement paste and aggregate in concrete. Compared to concrete with anatase phase NT, silica surface-treated rutile phase NT is more effective in improving the deterioration resistance of concrete in the marine environment. It can be concluded that incorporating NT can inhibit the deterioration of concrete in the marine environment.

An Experimental and Theoretical Study on the Effect of Silver Nanoparticles Concentration on the Structural, Morphological, Optical, and Electronic Properties of TiO2 Nanocrystals

In this work, pure and silver (Ag)-loaded TiO2 nanocrystals (NCs) with various concentrations of Ag were prepared by soft chemical route and the effect of Ag nanoparticles (NPs) on the functional properties of TiO2 was studied. X-ray diffraction (XRD) and Raman studies confirmed that the synthesized product had single-phase nature and high crystalline quality. The crystallite size was decreased from 18.3 nm to 13.9 nm with the increasing in concentration of Ag in TiO2 NCs. FESEM micrographs showed that the pure and AgNPs-loaded TiO2 have spherical morphology and uniform size distribution with the size ranging from 20 to 10 nm. Raman spectroscopy performed on pure and AgNPs-loaded TiO2 confirms the presence of anatase phase and AgNPs. Optical properties show the characteristics peaks of TiO2 and the shifting of the peaks position was observed by changing the concentration of Ag. The tuning of bandgap was found to be observed with the increase in Ag, which could be ascribed to the synergistic effect between silver and TiO2 NCs. Density functional theory calculations are carried out for different Ag series of doped TiO2 lattices to simulate the structural and electronic properties. The analysis of the electronic structures show that Ag loading induces new localized gap states around the Fermi level. Moreover, the introduction of dopant states in the gap region owing to Ag doping can be convenient to shift the absorption edge of pristine TiO2 through visible light.