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Supporting information (SI)
Dynamics of photogenerated charges in the phosphate modified TiO2
and the enhanced activity for photoelectrochemical water splitting
Liqiang Jing†, ‡, *, Jia Zhou‡, James R. Durrant†, Junwang Tang§,
Dening Liu‡, Honggang Fu‡
† Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK;
‡Key Lab of Functional Inorganic Materials Chemistry (Heilongjiang University), Ministry of Education,
School of Chemistry and Materials Science, Harbin 150080, P. R. China;
§Department of Chemical Engineering, University London WC1E7JE, UK. College London, Torrington Place
*Address correspondence to [email protected].
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
SI-I
high
SEM images
h magnificatio
s (A: TF, B:
on).
A
B
0.1P-TF, and
d C: 0.5P-TF.. Inset shows the correspoonding image
2
with
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
3
SI-II Uv-Vis spectra (TF and 0.1P-TF).
350 400 450 500 550 6000.0
0.5
1.0
1.5
2.0 TF 0.1P-TF
Abs
orpt
ion
/ a.
u.
Wavelength (nm)
C
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
4
SI-III XPS spectra of Ti2p (A), O1s (B) and P2p (C).
452 456 460 464 468
Inte
nsi
ty /
a.u
.
Binding energy / eV
TF
0.1P-TF
0.5P-TF
A Ti2p
524 526 528 530 532 534 536 538
O1s
Inte
nsi
ty /
a.u
.
Binding energy / eV
TF
0.1P-TF
0.5P-TF
B
126 128 130 132 134 136 138
nP/nT= 0.04
Inte
nsi
ty /
a.u
.
Binding energy / eV
0.1P-TF
0.5P-TF
C P2p
nP/nT= 0.08
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
5
SI-IV Temporal profile of transient absorption spectra of photoelectrons and photoholes of TF (A)
and 0.1P-TF (B) in argon.
1E-6 1E-5 1E-4 1E-3 0.01 0.10.0
0.5
1.0
1.5
2.0
s
O
D (
No
rmal
ized
)
Log(time) / s
TF in Ar 450 800
A
1E-6 1E-5 1E-4 1E-3 0.01 0.10.0
0.5
1.0
1.5
2.0B
s
Log(time) / s
O
D (
No
rmal
ized
)
0.1P-TF in Ar 450 800
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
6
SI-V I-V curves of TF and 0.1P-TF under illumination (solid line) and in the dark (dash line).
Potentials were measured against a Ag/AgCl (saturated KCl solution) reference electrode in an
argon-bubbled 0.5 M NaClO4 solution, in which the pH value was altered by adding
desired-amount HCl or NaOH solution.
-1.0 -0.5 0.0 0.5 1.0 1.5
0
20
40
60
80
100 pH12, under illumination pH7, under illumination pH12, in the dark pH7, in the dark
Cu
rren
t d
ensi
ty (A
/ cm
2 )
Potential (V) vs Ag/AgCl
TF
-0.5 0.0 0.5 1.0 1.50
20
40
60
80
100
Cur
rent
den
sity
(A
/ cm
2 )
Potential (V) vs Ag/AgCl
pH7, under illumination pH2, under illumination pH2, in the dark pH7, in the dark
0.1P-TF
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
7
SI-VI I-t curves of different TiO2 film electrodes under illumination and in the dark. Potentials are
measured against a Ag/AgCl (saturated KCl solution) reference electrode in an argon-bubbled 0.5
M NaClO4 solution. (TF: black, 0.1P-TF: green, 0.3P-TF: blue, and 0.5P-TF: cyan)
0 100 200 300 400 500 6000
20
40
60
DarkDarkDark
LightLight
Cu
rren
t d
ensi
ty (A
/ cm
2 )
Time / s
0.1P-TFTF0.3P-TF0.5P-TF
Light
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
8
SI-VII Temporal profile of transient absorption spectra of photoelectrons and
photoholes of TF in pH2 water (Inset means surface carried charges of TiO2).
1E-6 1E-5 1E-4 1E-30.0
0.5
1.0
1.5
2.0
O
D (
No
rmal
ized
) T450 T800
TF in pH2 water
Log(time) / s
2 s
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012
9
SI-VIII I-V curves of TF under illumination (solid line) and in the dark (dash line). Potentials
were measured against a Ag/AgCl (saturated KCl solution) reference electrode in an
argon-bubbled 0.5 M NaClO4 solution, in which the pH value was altered by adding
desired-amount HCl solution.
-0.4 0.0 0.4 0.8 1.20
20
40
60
80
100
pH7 (under illumination) pH2 (under illumination) pH2 (in the dark) pH7 (in the dark)
Cur
rent
den
sity
(A
/cm
2 )
Potential (V) vs Ag/AgCl
TF
Electronic Supplementary Material (ESI) for Energy & Environmental ScienceThis journal is © The Royal Society of Chemistry 2012