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Low-temperature synthesis of CuO-interlaced nanodiscs for lithium ion battery electrodes.

Seo SD, Jin YH, Lee SH, Shim HW, Kim DW - Nanoscale Res Lett (2011)

Bottom Line: After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs.The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling.Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, Ajou University, Suwon 443-749, Korea. dwkim@ajou.ac.kr.

ABSTRACT
In this study, we report the high-yield synthesis of 2-dimensional cupric oxide (CuO) nanodiscs through dehydrogenation of 1-dimensional Cu(OH)2 nanowires at 60°C. Most of the nanodiscs had a diameter of approximately 500 nm and a thickness of approximately 50 nm. After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs. These CuO nanostructures were characterized using X-ray diffraction, transmission electron microscopy, and Brunauer-Emmett-Teller measurements. The possible growth mechanism of the interlaced disc CuO nanostructures is systematically discussed. The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling. Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

No MeSH data available.


FESEM images. (a) [Cu(NH3)4]2+ complex, (b) Cu(OH)2 nanowires at room temperature, (c-d) Cu(OH)2 nanowires after reaching 40°C and 50°C, respectively. (e-f) CuO-interlaced nanodiscs at 60°C after 0 and 3 h, respectively. (g) Schematic diagram of the morphology evolution steps for CuO nanostructures.
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Figure 2: FESEM images. (a) [Cu(NH3)4]2+ complex, (b) Cu(OH)2 nanowires at room temperature, (c-d) Cu(OH)2 nanowires after reaching 40°C and 50°C, respectively. (e-f) CuO-interlaced nanodiscs at 60°C after 0 and 3 h, respectively. (g) Schematic diagram of the morphology evolution steps for CuO nanostructures.

Mentions: To understand the growth mechanism of the above CuO-interlaced nanodisc structures, temperature- and time-dependent experiments were carried out. Figure 2 shows the series of typical FESEM images of samples taken after reaching a preset temperature and time. First, Cu2+ ions in the CuSO4 solution formed a square-planar complex [Cu(NH3)4]2+ upon addition of NH3OH at room temperature [17]. When NaOH was further added, Cu(OH)2 nanocrystals began to precipitate. The template-free formation of a 1-D nanowire morphology with a 30- to 50-nm diameter was due to the specific crystal structure of Cu(OH)2 (Figure 2b), because the growth of the layer-structured orthorhombic Cu(OH)2 along [100] was much faster than along any other direction, leading to a tendency to form a 1-D structure [10,14,15,18]. With the increase in the reaction temperature from room temperature to 50°C, each nanowire was shortened and thickened laterally due to the oriented attachment of the Cu(OH)2 nanowires (Figure 2c,d) [17-20]. Meanwhile, a gradual dehydration involving conversion from Cu(OH)2 to CuO might occur.


Low-temperature synthesis of CuO-interlaced nanodiscs for lithium ion battery electrodes.

Seo SD, Jin YH, Lee SH, Shim HW, Kim DW - Nanoscale Res Lett (2011)

FESEM images. (a) [Cu(NH3)4]2+ complex, (b) Cu(OH)2 nanowires at room temperature, (c-d) Cu(OH)2 nanowires after reaching 40°C and 50°C, respectively. (e-f) CuO-interlaced nanodiscs at 60°C after 0 and 3 h, respectively. (g) Schematic diagram of the morphology evolution steps for CuO nanostructures.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211491&req=5

Figure 2: FESEM images. (a) [Cu(NH3)4]2+ complex, (b) Cu(OH)2 nanowires at room temperature, (c-d) Cu(OH)2 nanowires after reaching 40°C and 50°C, respectively. (e-f) CuO-interlaced nanodiscs at 60°C after 0 and 3 h, respectively. (g) Schematic diagram of the morphology evolution steps for CuO nanostructures.
Mentions: To understand the growth mechanism of the above CuO-interlaced nanodisc structures, temperature- and time-dependent experiments were carried out. Figure 2 shows the series of typical FESEM images of samples taken after reaching a preset temperature and time. First, Cu2+ ions in the CuSO4 solution formed a square-planar complex [Cu(NH3)4]2+ upon addition of NH3OH at room temperature [17]. When NaOH was further added, Cu(OH)2 nanocrystals began to precipitate. The template-free formation of a 1-D nanowire morphology with a 30- to 50-nm diameter was due to the specific crystal structure of Cu(OH)2 (Figure 2b), because the growth of the layer-structured orthorhombic Cu(OH)2 along [100] was much faster than along any other direction, leading to a tendency to form a 1-D structure [10,14,15,18]. With the increase in the reaction temperature from room temperature to 50°C, each nanowire was shortened and thickened laterally due to the oriented attachment of the Cu(OH)2 nanowires (Figure 2c,d) [17-20]. Meanwhile, a gradual dehydration involving conversion from Cu(OH)2 to CuO might occur.

Bottom Line: After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs.The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling.Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, Ajou University, Suwon 443-749, Korea. dwkim@ajou.ac.kr.

ABSTRACT
In this study, we report the high-yield synthesis of 2-dimensional cupric oxide (CuO) nanodiscs through dehydrogenation of 1-dimensional Cu(OH)2 nanowires at 60°C. Most of the nanodiscs had a diameter of approximately 500 nm and a thickness of approximately 50 nm. After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs. These CuO nanostructures were characterized using X-ray diffraction, transmission electron microscopy, and Brunauer-Emmett-Teller measurements. The possible growth mechanism of the interlaced disc CuO nanostructures is systematically discussed. The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling. Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths.

No MeSH data available.