Electrochemical Anodization and Characterization of Titanium Oxide Nanotubes for Photo Electrochemical Cells

Due to its multitude of applications, titanium oxide is one of the most coveted and most sought-after materials. The above experiment demonstrated that TiO2 nanotube arrays might be formed by electrochemical anodization of titanium foil. The 0.25 wt% ammonium fluoride (NH4F) was added to a solution of 99% ethylene glycol. Anodization is carried out at a constant DC voltage of 12V for 1 hour. Then, the annealing process is carried out for 1 hour at 4800C, which is known as an annealing. FE-SEM were utilized to evaluate the surface morphology of the nanotube arrays that were made. At the wavelength of 405 nm, sharply peaked photoluminescence intensity was observed, which corresponded tothe band gap energy (3.2 eV) of the anatase TiO2 phase. Since free excitations appear at 391 and 496 nm, and since oxygen vacancies are developed on the surface of titania nanotube arrays, it is reasonable to conclude that free excitations and oxygen vacancies are the causes of humps at 391 and 496 nm, and that they may also be present at 412 and 450 nm. FESEM results showed uniformly aligned TiO2 nanotube arrays with an inner diameter of 100 nm and a wall thickness of 50 nm

Fabrication and characterization of chitosan-titanium oxide nanotubes scaffolds reinforced with tiger milk mushroom

Chitosan-based scaffolds have been reported to promote cellular activities but lack mechanical strength which is much sought after for bone regeneration. The current research work aided to reinforce chitosan-based scaffolds with tiger milk mushroom (TMM) powder, a naturally occurring polysaccharide. Scaffolds of chitosan-titanium oxide nanotubes (TNTs) reinforced with tiger milk mushroom (TMM-CTNTs) were fabricated via direct-blending and freeze-drying methods. Prior to that, TNTs were hydrothermally synthesized and blended with chitosan solution and TMM powder at 1-5 weight percent (wt %). The pore size, microstructure, porosity, swelling, degradation, compressive modulus and functional groups of resultant scaffolds were characterized. These cylindrical scaffolds of TMM-CTNTs showed pore size of 48 – 68 μm. The addition of TMM from 3 wt% to 5 wt% in scaffolds reduced the porosity from 81.7 % to 79.9 %. The compressive modulus of 3 wt%-5 wt% TMM-CTNTs scaffolds increased %from 0.013 MPa – 0.038 MPa. The incorporation of TMM influenced the swelling property of scaffolds. The swelling percentage of TMM-CTNTs reduced from 400% to 373% as TMM powder was introduced from 1 wt% to 5 wt%. The degradation ratio increased from 0.959% to 2.385 % as TMM powder was introduced from 1 wt% to 5 wt%. The Fourier-Transform Infrared (FTIR) spectra of TMM-CTNTs scaffolds revealed the presence of β-glucan which verified that the processing methods in this study preserved the medicinal property of TMM. A preliminary in vitro test, MTT assay, was used to study proliferation rate of MG63 (osteoblast-like cells) cultured on TMM-CTNTs scaffolds with different weight percent of TMM. Notably, the cells proliferation of MG63 showed high biocompatibility at 3 days of culture.

Comparison of Different Synthetic Routes of Hybrid Hematite-TiO2 Nanotubes-Based Electrodes

Nowadays, green hydrogen is an important niche of interest in which the search for a suitable composite material is indispensable. In this sense, titanium oxide nanotubes (TiO2 nanotube, TNTs) were prepared from double anodic oxidation of Ti foil in ethylene glycol electrolyte. The morphology of the nanotubes was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Once characterized, nanotubes were used as templates for the deposition of hematite. The use of three synthetic procedures was assayed: Chemical Vapor Deposition (CVD), Successive Ionic Layer Adsorption and Reaction (SILAR), and electrochemical synthesis. In the first case, CVD, the deposition of hematite onto TiO2 yielded an uncovered substrate with the oxide and a negative shift of the flat band potential. On the other hand, the SILAR method yielded a considerable amount of hematite on the surface of nanotubes, leading to an obstruction of the tubes in most cases. Finally, with the electrochemical synthesis, the composite material obtained showed great control of the deposition, including the inner surface of the TNT. In addition, the impedance characterization showed a negative shift, indicating the changes of the interface electrode–electrolyte due to the modification with hematite. Finally, the screening of the methods showed the electrochemical synthesis as the best protocol for the desired material.