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Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
1
Supporting Information:
Photoelectrocatalytic Oxidation of NADH by Visible Light Driven Plasmonic Nanocomposites
Aneeya K Samantara, a,b,c
Subash Chandra Sahu, a,c
Bamaprasad Bag,a,c
Bijayalaxmi Jena b* and Bikash
Kumar Jena, a,c
*
a CSIR-Institute of Minerals and Materials Technology, Bhubaneswar-751013, Odisha, India.
b Department of Chemistry, Utkal University, Bhubaneswar-751004, Odisha, India.
c Academy of Scientific& Innovative Research, New Delhi-110001, India.
EXPERIMENTAL SECTION
Materials. Zn (CH3COOH) 2. 2H2O and Urea were purchased from Merck, India. HAuCl4 and Azure A
chloride were obtained from Sigma-Aldrich. Other chemicals used in this investigation were of analytical
grade and used without further purification. All solutions used during the experiments were prepared using
deionised water obtained from Millipore system.
Characterization. The as-synthesized RB-ZnO and RB-ZnO/Au were characterized by a field emission
scanning electron microscope (FE-SEM, ZEISS, Supra-55), X-ray diffraction (XRD), X’pert PRO (Pan
Analytical) X-ray diffraction unit using Ni filtered CuKα (λ = 1.54 Å) radiation, transmission electron
microscope (FEI, TECHNAI G2 transmission electron microscope operating at 200 kV ), UV-Vis absorption
Spectroscopy, SHIMADZU (UV-2600), X-ray photoelectron spectroscopy (Prevac, Poland), Raman
Instrument (Renishaw in Via Raman microscope).
Synthesis of Raspberry shaped ZnO nanostructure (RB-ZnO). Synthesis of Raspberry shaped ZnO
structure was carried out by adopting a facile microwave assisted solution phase approach. In a typical
procedure, Zn (CH3COOH)2. 2H2O and urea were taken in stoichiometric amount. This mixture was then
dissolved with minimum quantity of deionised water and then 50 ml of ethylene glycol was added to it. The
mixed solution was placed in the microwave instrument at 900 W for about 10 min. After the completion of
reaction, the product was thoroughly washed with copious amount of deionised water followed by absolute
ethanol and dried at 85 °C in a hot air oven.
Synthesis of AuNPs decorated RB-ZnO hybrid nanostructures (RB-ZnO/Au): The Functionalization of
the RB-ZnO structures was carried out by a simple wet chemical reduction method. In a typical procedure, 0.5
gm of the as synthesized RB-ZnO is dispersed in water via sonication and to it 5ml of certain percentage
HAuCl4 solution (0.01, 0.03, 0.05, 0.1 or 2%) was added. Then 800 µl of 0.002M NaBH4 was added by drop
wise under stirring condition. After 10 min the suspension was filtered, washed and placed in a hot air oven to
dry and stored in the desiccator prior to use.
Electrochemical Measurements. All the electrochemical measurements were carried out by taking a two
compartment three electrode cell. Here glassy carbon electrode is taken as the working electrode, a bare Pt
wire electrode as the counter and Ag/AgCl as the reference electrode. All the electrochemical measurements
were recorded in an argon atmosphere. The electrochemical measurements are recorded by using a computer
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2014
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
2
controlled CHI660C electrochemical work station. The as-synthesized nanoparticles are dispersed over glassy
carbon electrode with nafion and dried prior to electrochemical experiments.
The Photoelectric measurements were carried out by illuminating 1cm2 of the working electrode at
zero bias voltage against Ag/AgCl electrode in 0.01M Na2SO4 as the supporting electrolyte. Here the
Photocurrent action spectra was obtained with a 100W lamp (Luminous Intensity 530 (max) cd) and the
generated photocurrent signals were measured by the CHI 660C electrochemical work station. Similarly the
NADH Photoelectrocatalytic oxidation was carried out by taking 0.1M phosphate buffer (pH 7.2) solution as
the supporting electrolyte. The photon to electron conversion was calculated using a monochromatic light
(sodium low pressure vapor lamp, λ =589 nm).
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
3
Figure S1. EDAX of RB-ZnOs
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
4
Figure S2. SAED pattern of RB-ZnOs
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
5
Figure S3. UV-Visible spectrum of RB-ZnOs
200 300 400 500 600 700 800
Inte
nsi
ty(a
.u)
Wavelength(nm)
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
6
Figure S4. Raman spectra of RB-ZnOs
200 400 600 800 1000
574cm-1
437cm-1
Inte
nsi
ty(a
.u)
Ramanshift in (cm-1
)
337cm-1
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
7
Figure S5. UV-Visible spectrum of RB-ZnO/Au NCs
200 300 400 500 600 700 800
Ab
sorb
an
ce(a
.u)
Wavelength(nm)
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
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Figure S6. EDAX of RB-ZnO/Au
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
9
400 500 600
560 nm
465 nm
Inte
nsi
ty (
a.u
.)
Wavelength (nm)
398 nm
Figure S7. The photoluminescence spectra of as synthesized RB-ZnO. Excited at 320 nm
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
10
0.0 0.4 0.8 1.2 1.6 2.0 2.4
0.0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
Z
im1
05
Zrel105
0.05% Au
0.03% Au
0.01% Au
0.1% Au
2% Au
Figure S8. Impedance plot (Nyquist) for RB-ZnO/Au at different percentage of Au loading.
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
11
0.0 0.4 0.8 1.2
0.00
0.15
0.30
(d) ZnO-Dark
(c) ZnO-Light
(b) ZnO/Au-Dark
(a) ZnO/Au-Light
I /
mA
E/V (Ag/AgCl)
Figure S9. The CV for oxidation of NADH (0.5mM) at (a, b) RB-ZnO/Au and (c, d) RB-
ZnO modified electrodes in the presence (a, c) and absence (b,d) of light respectively.
Electrolyte: PBS medium (pH: 7.2). Scan rate: 10 mV/s
Supplementary Material (ESI) for J Mater. Chem. A
This Journal is (c) The Royal Society of Chemistry 2013
12
Table 1
Photocatalysts Oxidation Potential for NADH
RB-ZnO 0.73V
ZnO-Au(2%Au) 0.72V
ZnO-Au(0.1%Au) 0.69V
ZnO-Au(0.01%Au) 0.66V
ZnO-Au(0.03%Au) 0.64V
ZnO-Au(0.05%Au) 0.60V
-0.4 0.0 0.4 0.8 1.2
No
rm
ali
sed
Cu
rren
t
E/V(Ag/AgCl)
0.05% Au
0.03% Au
0.01% Au
0.1% Au
2% Au
Figure S10. The CV for oxidation of NADH (0.5mM) at different percentage of Au loaded
RB-ZnO/Au in the presence of light. Electrolyte: PBS (pH: 7.2). Scan rate: 10 mV/s. Table
1 shows the summarized oxidation potential of NADH at different electrodes.