Synthesis, Characterization, and Magnetic Properties of Uniform-sized MnO Nanospheres

and Nanorods

Jongnam Park,† Eunae Kang,† Che Jin Bae,‡ Je-Geun Park,‡ Han-Jin Noh,§ Jae-Young Kim,§ Jae-Hoon Park,§ Hyun Min Park,| and Taeghwan Hyeon*,

National CreatiVe Research InitiatiVe Center for Oxide Nanocrystalline Materials and School of Chemical Engineering, Seoul National UniVersity, Seoul 151-744, Korea, Department of Physics and Institute of Basic Sciences, Sungkyunkwan UniVersity, Suwon 440-746 Korea, Department

of Physics and Pohang AccelerationLaboratory, Pohang UniVersity of Science and Technology, Pohang, Kyungbuk 790-784, Korea, and New Material EValuation Center, Korea Research Institute of Standards and Science, Taejon

305-600, Korea

ReceiVed: April 22, 2004; In Final Form: July 5, 2004

報告人：許祐元指導教授：王聖璋

J. Phys. Chem. B 2004, 108, 13594-13598

Introduction

MnO2 is currently under extensive investigations for its capacitance properties.

manganese oxide nanostructures for their potential applications such as catalysis, rechargeable batteries, ionsieves and supercapacitors

the synthesis of MnO nanospheres and nanorods from the thermal decomposition of Mn-surfactant complexes

Experimental

Mn2(CO)10

0.2 g

Oleylamine2 mL

Trioctylphosphine(TOP)10 mL

Stirring At 100℃

complex

StirringAt 300 for 1hr℃

Triphenylphosphine(TPP)10 mL

J. Phys. Chem. B 2004, 108, 13594-13598

Figure 1. Transmission electron micrograph of 5-, 10-, and 40-nm monodisperse MnO nanoparticles.

Inject TOP Inject TPP Inject TOP At 100 for 2 days℃

J. Phys. Chem. B 2004, 108, 13594-13598

Results and discussion

Figure 2. Low-resolution transmission electron micrographs of (a) 7 x 33 nm and (b) 8 x 140 nm sized MnO nanorods, (c) high-resolution transmissionelectron micrograph, and (d) electron diffraction pattern of 8 140 nm sized MnO nanorods.

Inject TPPAt 330℃

Inject TOPAt 330℃

J. Phys. Chem. B 2004, 108, 13594-13598

MnO (JCPDS, 89-4835)

Figure 4. The powder X-ray diffraction (XRD) pattern of 8 140nm sized MnO nanorods.

M3O4 (JCPDS, 80-0382)

MnO (JCPDS, 07-0230)

Conclusion

we synthesized uniform-sized MnO nanospheres with particle sizes ranging from 5 to 40 nm from the thermal decomposition of Mn-surfactant complexes.

When TOP and TPP were employed as the surfactants, MnO nanorods with sizes of 7 nm (diameter) x 33 nm (length) and 8 nm (diameter) x 140 nm (length) were produced

precursor

Manganese(II) Acetate Tetrahydrate

oleic acid ℃/time

1 mmol 9 mmol 180 /30 min℃

injectOleylamine 18 mmol at 300 for 1hr℃

precursor

Manganese(II) Oxide oleic acid ℃/time

1 mmol 2 mmol 300 /30 min℃

Oleylamine 3 mmol at 300 for 30 min℃inject

Chem. Mater., Vol. 18, No. 7, 2006

Mn(HCOO)2 3 mmol + oleylamine 20 mmol at 340 for 5-10 min℃

MnO (JCPDS 75-1090)

Future work

MnO was dissolved in oleic acid at 300 for ℃30 min.

Try different reaction temperature and reaction time

Try different surfactant

Thanks for your attention