Shape-Controlled Synthesis of Manganese Oxide Octahedral Molecular Sieve Three-Dimensional Nanostructures

Abstract

Cryptomelane-type manganese oxide octahedral molecular (OMS) sieve three-dimensional (3D) nanostructures were synthesized via facile temple-free low-temperature hydrothermal reactions. Morphologies of the cryptomelane-type OMS-2 nanoparticles with tunnel dimension of 4.6 x 4.6 A can be tuned by varying reaction temperatures. At low temperature (120 degrees C), OMS-2 dendritic nanoclusters composed of uniform single-crystal nanotetragonal prisms with square cross-sections were formed. At high temperature (180 degrees C), the morphologies of OMS-2 became spherical dandelion-like microspheres composed of uniform single-crystal OMS-2 nanoneedles. Slow oxidation of Mn(2+) by Cr(2)O(7)(-) under hydrothermal conditions is critical for the formation of the hierarchically ordered OMS-2 3D nanostructures.

Ag2Se complex nanostructures with photocatalytic activity and superhydrophobicity

“…It is usually believed that the growth of nanostructures in solution involves two important processes, namely nucleation followed by growth [23]. In the case of our Ag 2 Se samples, these two processes are followed by assembly of the plateshaped structure.…”

Quantitative room-temperature mineralization of airborne formaldehyde using manganese oxide catalysts

“…It can be seen from SEM images of the laboratory synthesized manganese oxide that each nanospherical particle consisted of platelets that were aligned perpendicular to the spherical surface. This structural formulation is due to the hydrothermal precipitation method of synthesis of these materials, and suggests the presence of voids that can incorporate water in interstitial spaces [31][32].…”

New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy

“…The commercially available manganese oxide was found to be crystalline and had particles 2θ with well defined crystal shape and size greater than 2µm. It can be seen from SEM images of the laboratory synthesized manganese oxide that each nanospherical particle consisted of platelets that were aligned perpendicular to the spherical surface which is very similar to a honeycomb structure (Yuan et al, 2005, Yuan et al, 2003, Zhong et al, 2004. …”