The demand for fresh and clean water sources is increasing globally, and there is a need to develop novel routes to eliminate micropollutants and other harmful species from water. Photocatalysis is a ...promising alternative green technology that has shown great performance in the degradation of persistent pollutants. Titanium dioxide is the most used catalyst owing to its attractive physico-chemical properties, but this semiconductor presents limitations in the photocatalysis process due to the high band gap and the fast recombination of the photogenerated carriers. Herein, a novel photocatalyst has been developed, based on titanium dioxide nanofibers (TiO
NFs) synthesized by electrospinning. The TiO
NFs were coated by atomic layer deposition (ALD) to grow boron nitride (BN) and palladium (Pd) on their surface. The UV-Vis spectroscopy measurements confirmed the increase of the band gap and the extension of the spectral response to the visible range. The obtained TiO
/BN/Pd nanofibers were then tested for photocatalysis, and showed a drastic increase of acetaminophen (ACT) degradation (>90%), compared to only 20% degradation obtained with pure TiO
after 4 h of visible light irradiation. The high photocatalytic activity was attributed to the good dispersion of Pd NPs on TiO
-BN nanofibers, leading to a higher transfer of photoexcited hole carriers and a decrease of photogenerated electron-charge recombination. To confirm its reusability, recycling tests on the hybrid photocatalyst TiO
/BN/Pd have been performed, showing a good stability over 5 cycles under UV and visible light. In addition, toxicity tests as well as quenching tests were carried out to check the toxicity of the byproducts formed and to determine active species responsible for the degradation. The results presented in this work demonstrate the potential of TiO
/BN/Pd nanomaterials, and open new prospects for the preparation of tunable photocatalysts.
Among numerous efforts toward preparation of visible-light TiO.sub.2, recently design and control for chemical structure of TiO.sub.2 outermost surface have been paid strong attention to enhance ...photocatalytic performance. We have previously succeeded in direct synthesis of structurally well-controlled TiO.sub.2 with highly concentrated Ti.sup.3+ from metal titanium particle via single-mode magnetic microwave (SMMW)-assisted reactions. Here, we demonstrate synthesis of Ti.sup.3+ and interstitial nitrogen (N.sub.int) co-doped TiO.sub.2 in Ar/O.sub.2/N.sub.2 system during one-step SMMW-assisted reactions, where chemical structure of outermost surface is rigorously controlled. In addition, such one-step-generated TiO.sub.2 shows significant thermal stability which has not been achieved in previously reported deficient TiO.sub.2 even through several step reactions. Additionally, the synthesized co-doped TiO.sub.2 with specific surface structures shows superior visible-light photocatalytic performance for photo-degradation of rhodamine B. The mechanism of outermost surface formation is systematically investigated by characterizations of XRD, XPS, UV-Vis absorption and PL. It demonstrates that the specific TiO.sub.2 surface including highly concentrated Ti.sup.3+ and N.sub.int can be attributed to the rapid heat-dynamics during the reaction, which enhance the efficiency for separation of photo-excited carriers. The one-step SMMW-assisted reactions on metallic particle as bottom-up process will open new strategy for material design of functional metal oxides.
Category:
Hindfoot
Introduction/Purpose:
Distraction arthrodesis of the subtalar joint is performed to restore height and correct deformity in the case of subtalar joint arthrosis, malalignment of ...the rear foot, calcaneal fracture, or other pathologies. Historically, autograft or allograft bone blocks were used to restore natural alignment and improve hindfoot function. Although successful use has been reported, complications associated with donor site morbidity and size limitation for autograft, as well as additional complications including nonunion, graft collapse, and loss of alignment are common. Recently, innovative advancements have enabled the use of 3D printed porous titanium implants for use, improving the union rates and reduced risk of subsidence and graft collapse.
Methods:
6 patients with subtalar collapse and anterior ankle impingement were indicated for distraction subtalar arthrodesis. Surgery was performed with a lateral approach for the distraction arthrodesis using an off the shelf 3D printed subtalar wedge and a nitinol pseudoelastic fusion rod for stabilization and fixation. Patients were followed 6 months post op for fusion and alignment. Fusion was confirmed at 3 months with CT scans and alignment was monitored with weightbearing ankle X-rays.
Results:
3D wedge incorporation and sustained correction of height and alignment was maintained over time at the subtalar joint. There were no nonunions, 2 patients reports skin healing issues due to tension on the skin with wound closure. These healed with local wound care. Improvement in preoperative to postoperative tibiotalar sagittal plane alignment was observed in all patients.
Conclusion:
The use of a 3D printed titanium wedge for distraction Arthrodesis of the subtalar joint is a safe procedure and useful procedure in short-term follow-up. This procedure does provide improvement in the patients alignment and fusion occurs with in 3 months of surgery.
Indirect recoil implantation following a nuclear reaction is a technique used to activate the surface of materials that cannot be directly activated by a charged particle beam. This research focuses ...on the indirect activation of Kapton.sup.® foils, which serves as a model of plastic or plastic coated surface activation. The alpha particle primary beam, produced by a cyclotron accelerator hits a stack of titanium and Kapton.sup.® interlaced foils. The implanted activity in the Kapton.sup.® foils is presented as a function of the primary beam energy for two separate implanted radioisotopes .sup.51Cr and .sup.48V, having suitable nuclear parameters for tracing in engineering experiments.
In this review article, attention is paid towards the formation of various nanostructured stoichiometric titanium dioxide (TiO
), non-stoichiometric titanium oxide (TiO
) and Magnéli phase (Ti
O
...)-based layers, which are suitable for the application in gas and volatile organic compound (VOC) sensors. Some aspects related to variation of sensitivity and selectivity of titanium oxide-based sensors are critically overviewed and discussed. The most promising titanium oxide-based hetero- and nano-structures are outlined. Recent research and many recently available reviews on TiO
-based sensors and some TiO
synthesis methods are discussed. Some promising directions for the development of TiO
-based sensors, especially those that are capable to operate at relatively low temperatures, are outlined. The applicability of non-stoichiometric titanium oxides in the development of gas and VOC sensors is foreseen and transitions between various titanium oxide states are discussed. The presence of non-stoichiometric titanium oxide and Magnéli phase (Ti
O
)-based layers in 'self-heating' sensors is predicted, and the advantages and limitations of 'self-heating' gas and VOC sensors, based on TiO
and TiO
/TiO
heterostructures, are discussed.
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