Pt-Decorated TiO2 Materials Supported on Carbon : Increasing Activities and Stabilities toward the ORR by Tuning the Pt Loading

Pt nanoparticles (Pt NPs) supported on carbon have been widely employed as electrocatalysts toward oxygen reduction reaction. The development of more efficient electrocatalysts that enable one to reduce or even not require the use of Pt is a central challenge. In addition to the control over the physical and chemical features of Pt NPs, metal support interactions can be employed to enhance activities via the generation and exposure of surface-active sites. In this context, we report herein the development of electrocatalysts composed of Pt NPs supported on TiO2 microspheres, that were subsequently impregnated onto carbon. We have found that, by optimizing the loading of Pt at the TiO2 surface, the electrocatalytic activity toward the ORR could be improved compared to that of the commercial Pt/C (E-TEK) material, even at lower Pt loadings. The enhancement in activities could be assigned to the balance between Pt loading and generation of reactive surface sites, such as adsorbed oxygenated species. Moreover, the utilization of TiO2 as support enabled improved stabilities relative to Pt/C (E-TEK). We believe that the results described herein may inspire the development of electrocatalysts for the ORR with improved activities and stabilities.Peer reviewe

Angiogenesis in tissue engineering : Breathing life into constructed tissue substitutes

Long-term function of three-dimensional (3D) tissue constructs depends on adequate vascularization after implantation. Accordingly, research in tissue engineering has focused on the analysis of angiogenesis. For this purpose, 2 sophisticated in vivo models (the chorioallantoic membrane and the dorsal skinfold chamber) have recently been introduced in tissue engineering research, allowing a more detailed analysis of angiogenic dysfunction and engraftment failure. To achieve vascularization of tissue constructs, several approaches are currently under investigation. These include the modification of biomaterial properties of scaffolds and the stimulation of blood vessel development and maturation by different growth factors using slow-release devices through pre-encapsulated microspheres. Moreover, new microvascular networks in tissue substitutes can be engineered by using endothelial cells and stem cells or by creating arteriovenous shunt loops. Nonetheless, the currently used techniques are not sufficient to induce the rapid vascularization necessary for an adequate cellular oxygen supply. Thus, future directions of research should focus on the creation of microvascular networks within 3D tissue constructs in vitro before implantation or by co-stimulation of angiogenesis and parenchymal cell proliferation to engineer the vascularized tissue substitute in situ

Engineering the Surface/Interface Structures of Titanium Dioxide Micro and Nano Architectures towards Environmental and Electrochemical Applications

Titanium dioxide (TiO2) materials have been intensively studied in the past years because of many varied applications. This mini review article focuses on TiO2 micro and nano architectures with the prevalent crystal structures (anatase, rutile, brookite, and TiO2(B)), and summarizes the major advances in the surface and interface engineering and applications in environmental and electrochemical applications. We analyze the advantages of surface/interface engineered TiO2 micro and nano structures, and present the principles and growth mechanisms of TiO2 nanostructures via different strategies, with an emphasis on rational control of the surface and interface structures. We further discuss the applications of TiO2 micro and nano architectures in photocatalysis, lithium/sodium ion batteries, and Li–S batteries. Throughout the discussion, the relationship between the device performance and the surface/interface structures of TiO2 micro and nano structures will be highlighted. Then, we discuss the phase transitions of TiO2 nanostructures and possible strategies of improving the phase stability. The review concludes with a perspective on the current challenges and future research directions

Rapid thermally processed hierarchical titania-based hollow fibres with tunable physicochemical and photocatalytic properties

A series of photocatalytic TiO2–carbon composite hollow fibres (HFs) was prepared in this study by a wet-dry phase inversion spinning method followed by a rapid thermal processing (RTP). The RTP method consists of two stages: (1) calcination at 800 °C for 15 min encased in a quartz tube followed by (2) a short open heating exposure at 800 °C for 0 to 7.5 min in air. The innovative two-stage RTP method led to a time saving of more than 90%. Results revealed that the pyrolysis conditions during the second stage of HF fabrication were essential to the final physical and chemical properties of resultant TiO2-carbon HFs, such as TiO2 crystallinity and carbon content, mechanical, textural and electronic properties, as well as photocatalytic reactivity. The best results show that HFs pyrolysed for a short duration (< 2 min) in the second stage produced a high microporous surface area of 217.8 m2·g−1, a good mechanical strength of 11 MPa and a TiO2 anatase-to-rutile (A/R) ratio of 1.534 on the HF surface. The HFs also achieved a 68% degradation of acid orange 7 dye with a kapp of 0.0147 min−1 based on a Langmuir-Hinshelwood model during the photocatalysis under UV light. Thus, this work provides a new synthesis protocol with significant time and cost savings to produce high-quality HFs for wastewater treatment

Formulation and Evaluation of Capecitabine Immediate Release Tablets

The Oral route of administration still continues to be the most preferred route due to its manifold advantages including ease of administration, accurate dosage, self-medication, versatility and most importantly patient compliance. Therefore, oral solid dosage forms are more popular. In the present work efforts have been made to develop Capecitabine Immediate Release (IR) tablets by direct compression and wet granulation technique. The drug release profile enhanced using SSG and compared with innovator drug product. The results showed that the release of the drug was depended on Sodium starch glycolate, super disinttegrant used at intra-granular and extra-granular state

Photocatalytic Adsorbents Nanoparticles

Photocatalysis and high adsorption coupling in a same nanoparticle have been emerged as a prominent class of cost-effective materials to degrade recalcitrant contaminants in wastewater. α-Hematite, metal-organic frameworks and TiO2 nanocomposites have been investigated due to their features that overcome the other conventional photocatalysts and adsorbents to remove contaminants in aqueous medium. Several methods are applied to synthesize these nanostructures with different properties and physicochemical features and a brief review is shown to these well-established techniques to provide an understanding for the construction and application of these advanced materials