Single-crystal tetragonal α-MnO2 nanorods with different amounts of gold nanoparticles (NPs) attached were successfully prepared by a facile sputtering deposition technique. Initially, the morphology and crystal structure of the bare α-MnO2 nanorods synthesized via a hydrothermal approach were investigated. Then, the amount of gold NPs at different sputtering times was analyzed. It was confirme...

The present research work describes an efficient method for facile synthesis of α-MnO2 nanorods by hydrothermal method and preparation of a series of polythiophene/manganese dioxide (PTh/MnO2) nanocomposites with various α-MnO2 ratios. These nanocomposites were fabricated by in-situ oxidative polymerization method using FeCl3 as oxidant, and characterized by Fourier transformed infrared (FT-IR)...

Large Li2O2 aggregations can produce high-capacity of lithium oxygen (Li-O2) batteries, but the larger ones usually lead to less-efficient contact between Li2O2 and electrode materials. Herein, a hierarchical cathode architecture based on different discharge characteristics of α-MnO2 and Co3O4 is constructed, which can enable the embedded growth of large Li2O2 aggregations to solve this problem...

Spinel zinc manganese oxide (ZnMn2O4) nanorods were successfully prepared using the previously synthesized α-MnO2 nanorods by a hydrothermal method as template. The nanorods were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Vis absorption, X-ray photoelectron spectroscopy, surface photovoltage spectroscopy, and Fourier transform infrared...

α-MnO2 nanorods were synthesized via the hydrothermal decomposition of KMnO4 in an acidic environment in the presence of Co2+ and Cr3+ ions. Reactions were carried out at three different temperatures: 90, 130 and 170 °C. All prepared samples exhibit a tetragonal MnO2 crystalline phase. SEM-EDS analysis shows that cobalt cations are incorporated to a higher degree into the MnO2 framework than ch...

We present synthesis, structure and magnetic properties of structurally well-ordered single-crystalline b-MnO2 nanorods of 50–100 nm diameter and several lm length. Thorough structural characterization shows that the basic b-MnO2 material is covered by a thin surface layer (~2.5 nm) of a-Mn2O3 phase with a reduced Mn valence that adds its own magnetic signal to the total magnetization of the b-...

New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long MnO2 nanorods with a diameter ~20 nm are conformably coated with PANI layers and fastened between GO layers. The MnO2 nanorods incorporated ternary composites electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in...

Among all type of batteries, Lithium Air Batteries (LAB) are considered to be the most effective due their highest energy density around 11900 Wh/kg but there some major issues being faced by LAB such as large overpotential, poor cycle life, low current density, and decreased efficiency. The solution these is primarily dependent on proper selection an electrocatalyst. A new approach for using a...

Development of catalysts for the electrochemical oxygen reactions, namely, reduction reaction (ORR) and evolution (OER), is critical application various renewable energy technologies. The aim this work to prepare low-cost MnO2 electrocatalyst with high activity ORR OER via introduction surface vacancies (OVs). Herein, procedure thermal heating treatment under air or H2 has been demonstrated as ...

This work presented a novel core-shell MnO2@m-SiO2 for catalyzing the removal of dyes from wastewater. MnO2 nanorods were sequentially coated with polydopamine (PDA) and polyethyleneimine (PEI) forming MnO2@PDA-PEI. By taking advantage of the positively charged amine groups, MnO2@PDA-PEI was further silicificated, forming MnO2@PDA-PEI-SiO2. After calcination, the composite MnO2@m-SiO2 was final...