Supporting information
Self-assembly of hierarchical 3D starfish-like Co3O4 nanowire
bundles on nickel foam for high-performance supercapacitor
Libo Gao1, Shang Xu1, Chenyang Xue2, Zhenyin Hai2, Dong Sun1 and Yang Lu1,3,*
1
Department of Mechanical and Biomedical Engineering, City University of Hong
Kong, Hong Kong SAR, Kowloon 999077, Hong Kong;
2
Science and Technology on Electronic Test and Measurement Laboratory, North
University of China, Taiyuan 030051, China;
3
Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057,
China
* Author to whom correspondence should
[email protected] ; Tel.: +852-3442-4061.
be
addressed;
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Supplementary Results
S1. Raman analysis
Figure S1. Raman spectroscopy of Co3O4 scratched from nickel foam.
S2. XPS analysis
Figure S2. XPS spectra of the Co3O4: slow scan spectra of (a) Co 2p; (b) high resolution XPS of Co
2p3/2 (c) O 1s; (c) full survey scan spectrum.
S3. SEM image of single precursor product
Figure S3. SEM image of single starfish-like Co(OH)F nanowire bundles.
S4. Nickel foam activation
Figure S4. (a) (b) SEM images of the nickel foam without activation; (c) (d) SEM images of the
activated nickel foam using hydrochloric acid.
S5. SEM image of Co3O4 nanowire bundles
Figure S5. High magnification of the starfish-like Co3O4 nanowire bundles constructed by single
nanowire.
S6. The unique structured hexagonal nanoplate with opening circular hole
Figure S6. (a)(b) Unique structured hexagonal nanoplates with opening circular hole (∼4 um)
mingled with the snowflake shaped Co3O4.
S7. Brunauer-Emmett-Teller (BET) surface areas and Barrett-Joyner-Halenda
(BJH) pore size distribution.
Figure S7.Brunauer-Emmett-Teller (BET) surface areas and Barrett-Joyner-Halenda (BJH) pore size
distributions.
S8. Result of the Co3O4 nanowire bundles after 1000 charge-discharged cycles
Reference electrode Counter electrode
(a)
Working electrode
(b)
10 um
Figure S8. (a) Digital photograph of the three-electrode system produced with 3M KOH electrolyte.
The photography was taken after the 1000-cycles galvanostatic charge-discharge test performed at a
current density of 12.5 A·g-1(b) SEM images of starfish-like Co3O4 after 1000 charge-discharged
cycles.