Highly regular TiO 2 nanotube arrays (TNTs) with interstitial nitrogen as the dominant point defect have been successfully prepared by annealing the as-anodized TNTs in N 2 in a temperature range of 400–650 °C. Using analysis methods that include field emission scanning electron microscopy, X-ray diffraction patterns, and Raman spectroscopy, the thermal stability of TNTs annealed in N 2 was found to be higher than that of TNTs annealed in O 2 . The interstitial nitrogen is considered as the dominant point defect in TNTs annealed in N 2 , which results in the notably improved thermal stability of the highly ordered TNTs. However, the content of hydroxyl oxygen on the surface of TNTs is significantly influenced by annealing temperature, which is closely related to photocatalytic activity. Optimized photocatalytic property of photodegradation of MO with a pseudo-first-order reaction constant k value of (5.065 ± 0.139) × 10 –2 h −1 is achieved for TNTs annealed in N 2 at 600 °C. These findings serve to provide simple and versatile guidelines to fabricate highly ordered TNTs with controllable point defects, enhanced thermal stability, and a high level of photocatalytic activity.
Anodic TiO 2 nanotubes have been intensively studied for the application in supercapacitors , but the formation of nanograss is often avoided for the belief that it may retard capacitive performance. We fabricate TiO 2 nanotubes topped with nanograss by H 3 PO 4 solution soaking and hydrogenation doping, which in fact increases the capacitance of nanotubes in a fast and convenient way. The new structure exhibits an enhanced areal capacitance by up to 67.7% and by up to 23.5% after 2000 times of cycling. The capacitance generally increases with the nanotube length and reaches the maximum with an optimal nanograss length. The electric charge during hydrogenation doping is determined to quantify the general doping effect. Compared with ordinary nanotubes, nanograss has larger contact area with electrolyte during doping. Therefore, the grass-topped structure yields more electric charge and Ti 3+ during doping, which attributes to the improved capacitance.
Cerium has been used as an implanted alloy additive for many years for it can enhance the mechanical properties of the alloy and restrain the corrosion of the implant. Moreover, cerium oxide nanoparticles are often used as an antibacterial material. However, there were few researches focusing on the antibacterial properties of Ce 3+ and Ce 4+ ions, instead of their corresponding oxide, as potential antibacterial coatings. Thus in this work, we loaded Ce ions into the porous structure of the ZIF-8 nanoparticles and co-deposited them with hydroxyapatite as a composite coating onto anodized titanium dioxide nanotubes array in order to test whether it can improve the anti-corrosion and antibacterial properties of the materials without affecting the biocompatibility.
危险品化学品经营许可证（带存储）