Supporting Information Au-ZnO hybrid nanopyramids and their photocatalytic properties Peng Li, Zhe Wei, Tong Wu, Qing Peng, and Yadong Li* State Key Laboratory of New Ceramics and Fine Processing, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China *E-mail:
[email protected] Experimental Details Synthesis of Au nanocrystals (NCs) Au nanocrystals were prepared by a previously reported method[S1] with some modifications. Typically, HAuCl4·4H2O (0.5 mmol) were added to the mixed solution of oleylamine (20 ml) and tetralin (20 ml) at the given temperatures and stirred for a few minutes under N2. Then, tert-butylamine borane complex (1 mmol) was dissolved in 2 ml of tetralin and 2 ml of oleylamine and injected to the above solution. After 1h stirring, ethanol was added and the precipitate was collected by centrifugation. The final product was redispersed in hexane for further use.
Characterization: The size and morphology of the products were measured using transmission electron microscopy (TEM, JEOL JEM 1200EX working at 100 kV and FEI Tecnai G2 F20 S-Twin working at 200 kV). Energy dispersive spectroscopy was used to characterize the composition of the products. The phase purity of the as-prepared nanocrystals were characterized by XRD on a Bruker D8 Advance X-ray powder diffractometer with Cu Ka radiation (λ=1.5418 Å). UV-vis absorption spectra were obtained using a Hitachi U-3010 spectrophotometer. The room-temperature photoluminescence were measured on a Hitachi F-4500 fluorescence spectrophotometer with a xenon lamp source.
Photocatalytic Measurements For photocatalytic degradation of Rhodamine B (Rh B), the catalysts (0.03g, ZnO and Au-ZnO NCs calcined at 250oC) were added to the beaker containing 100 mL deionized water. After ultrasonication, Rh B dye (1mL, 1mmol/L) was injected to above solution and the mixture was continuously stirred in dark for 30 min. Then, the photocatalytic test was conducted by irradiation with a 300W Xenon lamp. The samples with different reaction time were taken out and centrifuged for the absorbance measurements using a Hitachi U-3010 spectrophotometer
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Supplementary Figures
Figure S1. TEM image of the as-prepared Au nanocrystals.
Figure S2. TEM image of the as-prepared Au-ZnO hybrid nanopyramids (NPs).
Figure S3. HRTEM images of the as-prepared Au-ZnO hybrid NPs. S2
Figure S4. The XRD pattern of Au-ZnO hybrid NPs (a) and UV-vis absorption spectra of Au and Au-ZnO hybrid NCs dispersed in hexane, respectively (b); the inset is the roomtemperature PL spectrum of Au-ZnO hybrid NPs
Figure S5. TEM image (a) and HAADF-STEM image (b) of the Au-ZnO NPs.
Figure S6. the UV-vis absorption spectrum when the temperature raised to120 oC.
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Figure S7. the TEM image of ZnO and the corresponding UV-vis absorption spectrum.
Figure S8. the TEM image of Au-ZnO hybrid NPs calcined at 250 oC and time-dependent UV-vis absorption spectra for Rh B in the presence of Au-ZnO hybrid NPs under ultraviolet irradiation.
Reference [S1] Peng, S.; Lee, Y.; Wang, C.; Yin, H.; Dai, S.; Sun, S. H. Nano Res. 2008, 1, 229.
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