Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Photoinduced reactivity of titanium dioxide

Core/Shell Nanoparticles: Classes, Properties, Synthesis Mechanisms, Characterization, and Applications

Hollow micro-/nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-/nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed.

Hollow Micro-/Nanostructures: Synthesis and Applications**

TiO(2) is one of the most studied compounds in materials science. Owing to some outstanding properties it is used for instance in photocatalysis, dye-sensitized solar cells, and biomedical devices. In 1999, first reports showed the feasibility to grow highly ordered arrays of TiO(2) nanotubes by a simple but optimized electrochemical anodization of a titanium metal sheet. This finding stimulated intense research activities that focused on growth, modification, properties, and applications of these one-dimensional nanostructures. This review attempts to cover all these aspects, including underlying principles and key functional features of TiO(2), in a comprehensive way and also indicates potential future directions of the field.

TiO2 nanotubes: synthesis and applications.

Novel penniform superstructures of BaWO4 nanowires have been successfully synthesized in catanionic reverse micelles by using a double-hydrophilic block copolymer as the directing agent. This synthetic method is very simple, mild, and controllable, and it provides a novel method for direct solution-growth of hierarchical nanostructures based on inorganic nanowires.

Polymer-directed synthesis of penniform BaWO4 nanostructures in reverse micelles.

Synthesis of Submicrometer‐Sized Hollow Silver Spheres in Mixed Polymer–Surfactant Solutions

A novel, wet chemical approach is reported for the facile synthesis of silver nanowires with diameters in the range of 20−40 nm in aqueous solutions of a double-hydrophilic block copolymer (DHBC) PEO-b-PMAA. Investigation of the time-dependent formation of the silver nanowires revealed that they were produced through a directed aggregation growth process and the formation of DHBC micelles could play an important role in nanowire formation.

Humin Cheng

Papers

Polymer-directed synthesis of penniform BaWO4 nanostructures in reverse micelles.

Synthesis of Submicrometer‐Sized Hollow Silver Spheres in Mixed Polymer–Surfactant Solutions

Formation of Silver Nanowires in Aqueous Solutions of a Double-Hydrophilic Block Copolymer

Morphosynthesis of Rhombododecahedral Silver Cages by Self‐Assembly Coupled with Precursor Crystal Templating

Large-pore mesoporous silica spheres: synthesis and application in HPLC