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Catalytic properties of Co3O4 nanoparticles for rechargeable Li/air batteries.

Kim KS, Park YJ - Nanoscale Res Lett (2012)

Bottom Line: The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles.It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles.This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Advanced Materials Engineering, Kyonggi University, San 94-6, Yiui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-760, Republic of Korea. yjpark2006@kyonggi.ac.kr.

ABSTRACT
Three types of Co3O4 nanoparticles are synthesized and characterized as a catalyst for the air electrode of a Li/air battery. The shape and size of the nanoparticles are observed using scanning electron microscopy and transmission electron microscopy analyses. The formation of the Co3O4 phase is confirmed by X-ray diffraction. The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles. It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles. This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

No MeSH data available.


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XRD patterns of the Co3O4 nanoparticles and reference Co3O4.
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Figure 2: XRD patterns of the Co3O4 nanoparticles and reference Co3O4.

Mentions: Scanning electron microscopy [SEM] and transmission electron microscopy [TEM] were employed to investigate the shapes of the samples (Figure 1). Cube-type Co3O4 nanoparticles have a homogeneous cubic morphology (Figure 1a). The length of the nanocube was around 200 nm, and the dominant exposed plane of the cube-type Co3O4 seemed to be {001}. The villiform-type Co3O4 particles were formed by a nucleus covered with numerous micrometer-sized nanorods. In comparison with the length, the diameter of the nanorod was very small (less than 100 nm). It is interesting that the villiform-type Co3O4 has a rough surface. As shown in the TEM image (Figure 1b), the nanorods seemed to be stacked with smaller nanoparticles with a diameter of approximately 80 nm. The flower-type Co3O4 seemed to have a similar shape and size to those of the villiform-type Co3O4. However, the nanorods of the flower-type Co3O4 had a sharper end, smoother surface, and smaller diameter than those of the villiform-type Co3O4. Moreover, in contrast with the villiform-type Co3O4, the nanorods of the flower-type Co3O4 particles were almost separated during the preparation process for the TEM experiments (Figure 1c). This implies that the flower-type Co3O4 particles may turn to the nanorod type during the electrode fabrication process because of vigorous mixing in making a slurry. The crystallinity of the three types of Co3O4 nanoparticles was investigated by XRD. As shown in Figure 2, all XRD peaks of the cube-type Co3O4 nanoparticles can be indexed to the Co3O4 spinel phase, indicating a single-phase sample. Most diffraction peaks for villiform- and flower-type Co3O4 particles were also identical to those of the typical Co3O4 phase; however, small impurities could be detected in the diffraction patterns.


Catalytic properties of Co3O4 nanoparticles for rechargeable Li/air batteries.

Kim KS, Park YJ - Nanoscale Res Lett (2012)

XRD patterns of the Co3O4 nanoparticles and reference Co3O4.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3275460&req=5

Figure 2: XRD patterns of the Co3O4 nanoparticles and reference Co3O4.
Mentions: Scanning electron microscopy [SEM] and transmission electron microscopy [TEM] were employed to investigate the shapes of the samples (Figure 1). Cube-type Co3O4 nanoparticles have a homogeneous cubic morphology (Figure 1a). The length of the nanocube was around 200 nm, and the dominant exposed plane of the cube-type Co3O4 seemed to be {001}. The villiform-type Co3O4 particles were formed by a nucleus covered with numerous micrometer-sized nanorods. In comparison with the length, the diameter of the nanorod was very small (less than 100 nm). It is interesting that the villiform-type Co3O4 has a rough surface. As shown in the TEM image (Figure 1b), the nanorods seemed to be stacked with smaller nanoparticles with a diameter of approximately 80 nm. The flower-type Co3O4 seemed to have a similar shape and size to those of the villiform-type Co3O4. However, the nanorods of the flower-type Co3O4 had a sharper end, smoother surface, and smaller diameter than those of the villiform-type Co3O4. Moreover, in contrast with the villiform-type Co3O4, the nanorods of the flower-type Co3O4 particles were almost separated during the preparation process for the TEM experiments (Figure 1c). This implies that the flower-type Co3O4 particles may turn to the nanorod type during the electrode fabrication process because of vigorous mixing in making a slurry. The crystallinity of the three types of Co3O4 nanoparticles was investigated by XRD. As shown in Figure 2, all XRD peaks of the cube-type Co3O4 nanoparticles can be indexed to the Co3O4 spinel phase, indicating a single-phase sample. Most diffraction peaks for villiform- and flower-type Co3O4 particles were also identical to those of the typical Co3O4 phase; however, small impurities could be detected in the diffraction patterns.

Bottom Line: The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles.It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles.This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Advanced Materials Engineering, Kyonggi University, San 94-6, Yiui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-760, Republic of Korea. yjpark2006@kyonggi.ac.kr.

ABSTRACT
Three types of Co3O4 nanoparticles are synthesized and characterized as a catalyst for the air electrode of a Li/air battery. The shape and size of the nanoparticles are observed using scanning electron microscopy and transmission electron microscopy analyses. The formation of the Co3O4 phase is confirmed by X-ray diffraction. The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles. It appears that the capacity of electrodes containing villiform-type Co3O4 nanoparticles is superior to that of electrodes containing cube- and flower-type Co3O4 nanoparticles. This is probably due to the sufficient pore spaces of the villiform-type Co3O4 nanoparticles.

No MeSH data available.


Related in: MedlinePlus