2
Luwei He, a
Shi-Zhao Kang,*
,a
Xiangqing Li, a
Lei Wang, b
Lixia Qin, a
and Jin Mu*
,a a School of Chemical and Environmental Engineering, Shanghai Institute of
Technology, 100 Haiquan Road, Shanghai, 201418, China b
School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
* Corresponding author: Jin Mu and Shi-Zhao Kang, Tel./fax: +86 21 60873061.
E-mail address: mujin@sit.edu.cn (J. Mu) and kangsz@sit.edu.cn (S.-Z. Kang)
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Supplementary
1. Preparation of ZnO “nanograss”
(1) An ITO substrate (2 cm×2 cm) was dried in N
2
stream at room temperature after cleaned ultrasonically with acetone, ethanol, and deionized water for 15 min, respectively. (2) The suspension of ZnO seeds was prepared using the method reported in ref. 9. (3) ZnO seeds were coated on the ITO substrate. (4) 30 mL aqueous solution containing zinc nitrate (25 mmol

L
-1
) and hexamethylenetetramine (25 mmol

L
-1
) was poured in a Teflon-lined stainless-steel autoclave. Then, the ITO substrate coated with ZnO seeds was immersed obliquely into the solution, and the surface loaded the ZnO seeds kept down. (5) After sealed, the autoclave was kept at
95

C for 3 h. Then, the autoclave was cooled down to room temperature, and the ITO substrate was rinsed three times with ethanol and deionized water, respectively.
Finally, the ITO substrate was dried with N
2
stream. (6) The ITO substrate with ZnO
“nanograss” was calcined at 350 
C for 3 h.
2. Preparation of ZnO “nanograss” loaded with Pt
The ITO substrate with the ZnO “nanograss” was immersed in the H
2
PtCl
6
solution
(40 mL, 0.3 mmol

L
-1
) for 1 h. Then, the ITO substrate was irradiated under UV light for 1 h. Finally, the ITO substrate was rinsed three times with deionized water.
3. Characterization
The Fielded Emission Scanning Electron Microscope (FESEM) images were taken using a Hitachi S4800 scanning electron microscope (Japan). The transmission electron microscope (TEM) images and the high resolution transmission electron
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microscope (HRTEM) image were taken with a JEOL JEM-2100 transmission electron microscope (Japan). The powder X-ray diffraction (XRD) analysis was performed on a PANalytical Xpert Pro MRD X-ray diffractometer (Netherlands). The
X-ray photoelectron spectra (XPS) were recorded with a Shimadzu Kratos AXIS Ultra
DLD X-ray photoelectron spectrometer (Japan). The N
2
adsorption and desorption isotherm was measured on a Micromeritics ASAP-2020 nitrogen adsorption apparatus
(USA). The UV-vis spectra were recorded on a Hitachi U-3900 UV-vis spectrophotometer (Japan). The fluorescence spectra were recorded on Hitachi F-4600 fluorescence spectrometer.
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Supplementary Fig. S1
75.1eV
78.5eV
72 74 76 78
Binding Energy (eV)
80 82
Fig. S1. High-resolution XPS spectrum (solid lines) of Pt 4f of the ZnO “nanograss” loaded with Pt.
Supplementary Fig. S2
1.6
1.6
Eosin Y-ZnO Film-Pt
Eosin Y-ZnO-Pt
ZnO nanoparticles film
ZnO "nanograss"
1.2
1.2
0.8
0.8
0.4
0.4
0.0
0.0
300 400 500 600
Wavelength (nm)
700 800 300 400 500 600
Wavelength (nm)
700 800
Fig. S2. UV-vis spectra of Eosin Y-ZnO-Pt, Eosin Y-ZnO Film-Pt, the ZnO
“nanograss” and the ZnO nanoparticles film.
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Supplementary Fig. S3
380nm
the ZnO "nanograss"
the ZnO "nanograss" with Pt
350 400 450 500
Wavelength (nm)
550 600
Fig. S3. F luorescence spectra of the ZnO “nanograss” and the Pt modified ZnO
“nanograss”.
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