Synthesis and applications of porous non-silica metal oxide submicrospheres

Abstract

Nowadays the development of submicroscale products of specific size and morphology that feature a high surface area to volume ratio, well-developed and accessible porosity for adsorbates and reactants, and are non-toxic, biocompatible, thermally stable and suitable as synergetic supports for precious metal catalysts is of great importance for many advanced applications. Complex porous non-silica metal oxide submicrospheres constitute an important class of materials that fulfill all these qualities and in addition, they are relatively easy to synthesize. This review presents a comprehensive appraisal of the methods used for the synthesis of a wide range of porous non-silica metal oxide particles of spherical morphology such as porous solid spheres, core-shell and yolk-shell particles as well as single-shell and multi-shell particles. In particular, hydrothermal and low temperature solution precipitation methods, which both include various structure developing strategies such as hard templating, soft templating, hydrolysis, or those taking advantage of Ostwald ripening and the Kirkendall effect, are reviewed. In addition, a critical assessment of the effects of different experimental parameters such as reaction time, reaction temperature, calcination, pH and the type of reactants and solvents on the structure of the final products is presented. Finally, the practical usefulness of complex porous non-silica metal oxide submicrospheres in sensing, catalysis, biomedical, environmental and energy-related applications is presented.

Nonsiliceous Mesoporous Materials: Design and Applications in Energy Conversion and Storage

“…The characteristics of some materials with representative secondary structures have been summarized ( Table 2 ). Methods to synthesize nonsiliceous materials have been reviewed …”

“…Methods to synthesize nonsiliceous materials have been reviewed. [43] Spheres and particles are the most common 0D mesoporous materials. Mesoporous carbon spheres can be obtained by the self-polymerization and spontaneous coassembly of diblock copolymer micelles.…”

One‐step Preparation of Monodisperse Multifunctional Macroporous Particles through a Spontaneous Physical Process

“…[1] Due to the short diffusion pathway, the minimal viscous effects and the effective intracellular endocytosis, they have been proven to perform better in various applications, including drug delivery, gene therapy, supercapacitors, Li-S batteries, and CO 2 capture, when compared with the monolith porous structures. [2] To fully results in a high size distribution of dispersed droplets, which in turn leads to a polydispersity of the final porous particles. It is well-known that monodispersity is a crucial feature for particles to repeat their high reliability and performance in multiple applications.…”

“…The design and preparation of porous polymer materials with particulate morphology have been pursued for decades in chemical and biological miniaturized systems . Due to the short diffusion pathway, the minimal viscous effects and the effective intracellular endocytosis, they have been proven to perform better in various applications, including drug delivery, gene therapy, supercapacitors, Li‐S batteries, and CO 2 capture, when compared with the monolith porous structures . To fully realize their potential and to optimize their performance, the following design criteria need to be simultaneously fulfilled: uniform sizes, controllable pore structure, and a versatile functionality.…”

Yolk–Shell‐Structured Cu/Fe@γ‐Fe2O3 Nanoparticles Loaded Graphitic Porous Carbon for the Oxygen Reduction Reaction

“…Generally, fabrication of yolk–shelled metal oxide nanoparticles involves multiple steps and often uses a combination of multiple synthesis methods. Hard templating is the most common method for creating yolk–shell structures; however, it also has distinctive drawbacks as a requisite step is needed to remove the templates, which always uses calcination in air or hazardous chemicals, and the removal step often causes a damage to the nanoparticles to some extent . Therefore, a facile and “green” process is highly desired to fabricate metal oxide yolk–shell nanoparticles.…”