skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Nanorods of manganese oxides: Synthesis, characterization and catalytic application

Abstract

Single-crystalline nanorods of {beta}-MnO{sub 2}, {alpha}-Mn{sub 2}O{sub 3} and Mn{sub 3}O{sub 4} were successfully synthesized via the heat-treatment of {gamma}-MnOOH nanorods, which were prepared through a hydrothermal method in advance. The calcination process of {gamma}-MnOOH nanorods was studied with the help of Thermogravimetric analysis and X-ray powder diffraction. When the calcinations were conducted in air from 250 to 1050 deg. C, the precursor {gamma}-MnOOH was first changed to {beta}-MnO{sub 2}, then to {alpha}-Mn{sub 2}O{sub 3} and finally to Mn{sub 3}O{sub 4}. When calcined in N{sub 2} atmosphere, {gamma}-MnOOH was directly converted into Mn{sub 3}O{sub 4} at as low as 500 deg. C. Transmission electron microscopy (TEM) and high-resolution TEM were also used to characterize the products. The obtained manganese oxides maintain the one-dimensional morphology similar to the precursor {gamma}-MnOOH nanorods. Further experiments show that the as-prepared manganese oxide nanorods have catalytic effect on the oxidation and decomposition of the methylene blue (MB) dye with H{sub 2}0009O.

Authors:
 [1];  [1];  [2];  [1];  [1];  [3];  [4]
  1. School of Chemical Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)
  2. School of Chemical Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China). E-mail: wxzhang@hfut.edu.cn
  3. Department of Chemistry and Institute of Nano Science and Technology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)
  4. Department of Chemistry and Institute of Nano Science and Technology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China). E-mail: chsyang@ust.hk
Publication Date:
OSTI Identifier:
20784909
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 179; Journal Issue: 3; Other Information: DOI: 10.1016/j.jssc.2005.11.028; PII: S0022-4596(05)00562-1; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CALCINATION; HEAT TREATMENTS; HYDROGEN PEROXIDE; MANGANESE OXIDES; METHYLENE BLUE; MONOCRYSTALS; NANOSTRUCTURES; THERMAL GRAVIMETRIC ANALYSIS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Yang Zeheng, Zhang Yuancheng, Zhang Weixin, Wang Xue, Qian Yitai, Wen Xiaogang, and Yang Shihe. Nanorods of manganese oxides: Synthesis, characterization and catalytic application. United States: N. p., 2006. Web. doi:10.1016/j.jssc.2005.11.028.
Yang Zeheng, Zhang Yuancheng, Zhang Weixin, Wang Xue, Qian Yitai, Wen Xiaogang, & Yang Shihe. Nanorods of manganese oxides: Synthesis, characterization and catalytic application. United States. doi:10.1016/j.jssc.2005.11.028.
Yang Zeheng, Zhang Yuancheng, Zhang Weixin, Wang Xue, Qian Yitai, Wen Xiaogang, and Yang Shihe. Wed . "Nanorods of manganese oxides: Synthesis, characterization and catalytic application". United States. doi:10.1016/j.jssc.2005.11.028.
@article{osti_20784909,
title = {Nanorods of manganese oxides: Synthesis, characterization and catalytic application},
author = {Yang Zeheng and Zhang Yuancheng and Zhang Weixin and Wang Xue and Qian Yitai and Wen Xiaogang and Yang Shihe},
abstractNote = {Single-crystalline nanorods of {beta}-MnO{sub 2}, {alpha}-Mn{sub 2}O{sub 3} and Mn{sub 3}O{sub 4} were successfully synthesized via the heat-treatment of {gamma}-MnOOH nanorods, which were prepared through a hydrothermal method in advance. The calcination process of {gamma}-MnOOH nanorods was studied with the help of Thermogravimetric analysis and X-ray powder diffraction. When the calcinations were conducted in air from 250 to 1050 deg. C, the precursor {gamma}-MnOOH was first changed to {beta}-MnO{sub 2}, then to {alpha}-Mn{sub 2}O{sub 3} and finally to Mn{sub 3}O{sub 4}. When calcined in N{sub 2} atmosphere, {gamma}-MnOOH was directly converted into Mn{sub 3}O{sub 4} at as low as 500 deg. C. Transmission electron microscopy (TEM) and high-resolution TEM were also used to characterize the products. The obtained manganese oxides maintain the one-dimensional morphology similar to the precursor {gamma}-MnOOH nanorods. Further experiments show that the as-prepared manganese oxide nanorods have catalytic effect on the oxidation and decomposition of the methylene blue (MB) dye with H{sub 2}0009O.},
doi = {10.1016/j.jssc.2005.11.028},
journal = {Journal of Solid State Chemistry},
number = 3,
volume = 179,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • Vanadium oxides nanorods with high crystallinity and high surface area were synthesized by hydrothermal method using laurylamine hydrochloride, metal alkoxide and acetylacetone. The samples characterized by XRD, nitrogen adsorption isotherm, SEM, TEM, and SAED. Uniformly sized B phase VO{sub 2} nanorods had widths about 40-80nm and lengths reaching up to 1{mu}m. V{sub 2}O{sub 5} rodlike structured with the widths about 100-500nm and the lengths of 1-10{mu}m were obtained by calcination at 400 deg. C for 4h. This synthesis method provides a new simple route to fabricate one-dimensional nanostructured metal oxides under mild conditions.
  • Graphical abstract: Prepared nanoferrites were characterized by FE-SEM and bright field TEM micrographs. The catalytic effect of these nanoferrites was evaluated on the thermal decomposition of ammonium perchlorate using TG and TG–DSC techniques. The kinetics of thermal decomposition of AP was evaluated using isothermal TG data by model fitting as well as isoconversional method. Display Omitted Highlights: ► Synthesis of ferrite nanostructures (∼20.0 nm) by wet-chemical method under different synthetic conditions. ► Characterization using XRD, FE-SEM, EDS, TEM, HRTEM and SAED pattern. ► Catalytic activity of ferrite nanostructures on AP thermal decomposition by thermal techniques. ► Burning rate measurements ofmore » CSPs with ferrite nanostructures. ► Kinetics of thermal decomposition of AP + nanoferrites. -- Abstract: In this paper, the nanoferrites of Mn, Co and Ni were synthesized by wet chemical method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive, X-ray spectra (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HR-TEM). It is catalytic activity were investigated on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellants (CSPs) using thermogravimetry (TG), TG coupled with differential scanning calorimetry (TG–DSC) and ignition delay measurements. Kinetics of thermal decomposition of AP + nanoferrites have also been investigated using isoconversional and model fitting approaches which have been applied to data for isothermal TG decomposition. The burning rate of CSPs was considerably enhanced by these nanoferrites. Addition of nanoferrites to AP led to shifting of the high temperature decomposition peak toward lower temperature. All these studies reveal that ferrite nanorods show the best catalytic activity superior to that of nanospheres and nanocubes.« less
  • Zinc oxide nanorods and diluted magnetic semiconducting Ni doped ZnO nanorods were prepared by thermal decomposition method. This method is simple and cost effective. The decomposition temperature of acetate and formation of oxide were determined by TGA before the actual synthesis process. The X-ray diffraction result indicates the single phase hexagonal structure of zinc oxide. The transmission electron microscopy and scanning electron microscopy images show rod like structure of ZnO and Ni doped ZnO samples with the diameter {approx} 35 nm and the length in few micrometers. The surface analysis was performed using X-ray photoelectron spectroscopic studies. The Ni dopedmore » ZnO exhibits room temperature ferromagnetism. This diluted magnetic semiconducting Ni doped ZnO nanorods finds its application in spintronics. - Highlights: Black-Right-Pointing-Pointer The method used is very simple and cost effective compared to all other methods for the preparation DMS materials. Black-Right-Pointing-Pointer ZnO and Ni doped ZnO nanorods Black-Right-Pointing-Pointer Ferromagnetism at room temperature.« less
  • The decomposition of hydrogen peroxide on thin layers of platinum-supported manganese oxides was studied in the stationary and nonstationary regions. The catalytic activities and the electrode potentials of the oxides were simultaneously determined. In the stationary region the surface's oxidation state and structure are independent of the temperature, of the hydrogen peroxide concentration, and of the presence of KCl and Mn/sup 2 +/ in the solution: the surface consists of a single phase. Hydrogen peroxide is transferred across the double layer in the form of neutral molecules. The catalytic activity was determined by the local properties of the surface.
  • The series Li{sub x}(Mn{sub y}Ni{sub 1{minus}y}){sub 2{minus}x}O{sub 2} for x {le} 1.33 and 0.38 {le} y {le} 0.50 shows a very close relationship to its parent series Li{sub x}Ni{sub 2{minus}x}O{sub 2}. The refined lattice parameters for at least 0.93 {le} x {le} 1.26 are a linear function of the concentration ratio Li/(Mn + Ni) which in turn is proportional to the averaged valence state of the transition metals. Li{sub x}(Mn{sub y}Ni{sub 1{minus}y}){sub 2{minus}x}O{sub 2} is able to reversibly coprecipitate/reinsert Li{sub 2}O and release/absorb O{sub 2}. This self-regulation mechanism seems to always adjust the number of cations to an undisturbed oxygenmore » sublattice according to the rule cations/anions = 1, which holds true at least for temperatures up to 800 C and oxygen partial pressures above 10{sup {minus}5} atm. Samples prepared in air and under O{sub 2} did not show nucleation of Li{sub 2}O, not even for x > 1.0. The series Li{sub x}(Mn{sub y}Ni{sub 1{minus}y}){sub 2{minus}x}O{sub 2} where 0.38 {le} y {le} 0.50 crystallizes in a rhombohedral unit cell (space group R{bar 3}m) for x < 1.15 and transforms into a single monoclinic phase (space group C2/c) for x > 1.25. The similarity between Li{sub x}Ni{sub 2{minus}x}O{sub 2} and Li{sub x}(Mn{sub y}Ni{sup 1{minus}y}){sub 2{minus}x}O{sub 2} strongly suggests a rhombohedral {r_arrow} cubic transition at x {approx} 0.6 for the latter series. Derived from the linear dependence of the X-ray density on the stoichiometric parameter x, an equation was found with which the lithium concentration of Li{sub x}(Mn{sub y}Ni{sub 1{minus}y}){sub 2{minus}x}O{sub 2} thin film phases over the entire range 0 {le} x {le} 1.33 can be determined accurately without extensive ion-beam analysis. XPS measurements on a film with the bulk stoichiometry Li{sub 1.10}Mn{sub 0.39}Ni{sub 0.51}O{sub 2} gave evidence for Mn{sup 4+} and Mn{sup 3+}, but no indication was found for nickel valence states other than Ni{sup 2+}. In order to meet the above-given stoichiometry, the averaged nickel valence state had to increase with film depth.« less