Fabrication and Elastic Properties of TiO2 Nanohelix Arrays through a Pressure-Induced Hydrothermal Method

Guidelines derived from biomineralized tissues for design and construction of high-performance biomimetic materials: from weak to strong

Living organisms in nature have undergone continuous evolution over billions of years, resulting in the formation of high-performance fracture-resistant biomineralized tissues such as bones and teeth to fulfill mechanical and biological functions, despite the fact that most inorganic biominerals that constitute biomineralized tissues are weak and brittle. During the long-period evolution process, nature has evolved a number of highly effective and smart strategies to design chemical compositions and structures of biomineralized tissues to enable superior properties and to adapt to surrounding environments. Most biomineralized tissues have hierarchically ordered structures consisting of very small building blocks on the nanometer scale (nanoparticles, nanofibers or nanoflakes) to reduce the inherent weaknesses and brittleness of corresponding inorganic biominerals, to prevent crack initiation and propagation, and to allow high defect tolerance. The bioinspired principles derived from biomineralized tissues are indispensable for designing and constructing high-performance biomimetic materials. In recent years, a large number of high-performance biomimetic materials have been prepared based on these bioinspired principles with a large volume of literature covering this topic. Therefore, a timely and comprehensive review on this hot topic is highly important and contributes to the future development of this rapidly evolving research field. This review article aims to be comprehensive, authoritative, and critical with wide general interest to the science community, summarizing recent advances in revealing the formation processes, composition, and structures of biomineralized tissues, providing in-depth insights into guidelines derived from biomineralized tissues for the design and construction of high-performance biomimetic materials, and discussing recent progress, current research trends, key problems, future main research directions and challenges, and future perspectives in this exciting and rapidly evolving research field.

Experimental Studies on TiO2 NT with Metal Dopants through Co-Precipitation, Sol-Gel, Hydrothermal Scheme and Corresponding Computational Molecular Evaluations

In the last decade, TiO₂ nanotubes have attracted the attention of the scientific community and industry due to their exceptional photocatalytic properties, opening a wide range of additional applications in the fields of renewable energy, sensors, supercapacitors, and the pharmaceutical industry. However, their use is limited because their band gap is tied to the visible light spectrum. Therefore, it is essential to dope them with metals to extend their physicochemical advantages. In this review, we provide a brief overview of the preparation of metal-doped TiO₂ nanotubes. We address hydrothermal and alteration methods that have been used to study the effects of different metal dopants on the structural, morphological, and optoelectrical properties of anatase and rutile nanotubes. The progress of DFT studies on the metal doping of TiO₂ nanoparticles is discussed. In addition, the traditional models and their confirmation of the results of the experiment with TiO₂ nanotubes are reviewed, as well as the use of TNT in various applications and the future prospects for its development in other fields. We focus on the comprehensive analysis and practical significance of the development of TiO₂ hybrid materials and the need for a better understanding of the structural-chemical properties of anatase TiO₂ nanotubes with metal doping for ion storage devices such as batteries.

Modulating Co-catalyst/Facet Junction for Enhanced Photoelectrochemical Water Splitting

Rational construction of electric field via assembling appropriate co-catalysts on anisotropic facets is of great significance for improving the photogenerated charge separation efficiency. However, this strategy usually gives rise to Fermi-level pinning which is not contributive to the charge separation but deleterious to the photoelectrochemical performance through consuming the measurable photovoltage. Herein, we demonstrate that manganese dioxide electrodeposited on the (111) facet of titanium dioxide nanorods could tremendously boost the catalytic activity of pristine photoanode via a stronger interface electric field and less photovoltage decay compared with the counterpart grown on the (110) facet. A photocurrent density of 1.65 mA·cm^-2 at 1.23 V (vs reversible hydrogen electrode), nearly the theoretical maximum of titanium dioxide, is achieved by the optimum photoanode with an extremely high separation efficiency of 95.15%. This study offers more in-depth insights into the design of carrier separation strategy through loading co-catalysts on different substrate surfaces for more efficient solar energy conversion.

Polymer-Based Nanofiber-Nanoparticle Hybrids and Their Medical Applications

The search for higher-quality nanomaterials for medicinal applications continues. There are similarities between electrospun fibers and natural tissues. This property has enabled electrospun fibers to make significant progress in medical applications. However, electrospun fibers are limited to tissue scaffolding applications. When nanoparticles and nanofibers are combined, the composite material can perform more functions, such as photothermal, magnetic response, biosensing, antibacterial, drug delivery and biosensing. To prepare nanofiber and nanoparticle hybrids (NNHs), there are two primary ways. The electrospinning technology was used to produce NNHs in a single step. An alternate way is to use a self-assembly technique to create nanoparticles in fibers. This paper describes the creation of NNHs from routinely used biocompatible polymer composites. Single-step procedures and self-assembly methodologies are used to discuss the preparation of NNHs. It combines recent research discoveries to focus on the application of NNHs in drug release, antibacterial, and tissue engineering in the last two years.