TY - JOUR
T1 - Preparation and photoelectrochemical characterization of porphyrin-sensitized α -Fe2 O3 thin films
AU - Herrera, Francisco V.
AU - Grez, Paula
AU - Schrebler, Ricardo
AU - Ballesteros, Luis A.
AU - Muoz, Eduardo
AU - Córdova, Ricardo
AU - Altamirano, Hernán
AU - Dalchiele, Enrique A.
PY - 2010
Y1 - 2010
N2 - The photoelectrochemical response of electrodeposited hematite (α -Fe2 O3) thin films, whose surface has been sensitized by the adsorption of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP), was studied. The α -Fe2 O3 thin films were obtained by the annealing of an electrodeposited Β -FeOOH precursor layer. The structural and morphological characteristics of the resulting hematite films were studied by X-ray diffraction, scanning electron microscopy, and atomic force microscopy techniques. The semiconducting characteristics of unmodified and sensitized TCPP hematite films were determined by electrochemical impedance measurements and by Mott-Schottky analysis. The hematite films exhibited an n-type behavior and a donor carrier concentration (ND =3× 1017 cm-3) for both unmodified and TCPP-sensitized ones. However, it was observed that the presence of TCPP shifts the energy of the surface states to higher values. The photoelectrochemical response of the unmodified and sensitized α -Fe2 O3 electrodes was followed by means of photovoltammetry and photocurrent-time transient techniques in a 0.1 M NaOHK+0.1 M KI solution under 25 mW/ cm2 white light illumination. The results showed that the photocurrent response exhibited by the TCPP-sensitized hematite films was 70% higher than the unmodified ones.
AB - The photoelectrochemical response of electrodeposited hematite (α -Fe2 O3) thin films, whose surface has been sensitized by the adsorption of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP), was studied. The α -Fe2 O3 thin films were obtained by the annealing of an electrodeposited Β -FeOOH precursor layer. The structural and morphological characteristics of the resulting hematite films were studied by X-ray diffraction, scanning electron microscopy, and atomic force microscopy techniques. The semiconducting characteristics of unmodified and sensitized TCPP hematite films were determined by electrochemical impedance measurements and by Mott-Schottky analysis. The hematite films exhibited an n-type behavior and a donor carrier concentration (ND =3× 1017 cm-3) for both unmodified and TCPP-sensitized ones. However, it was observed that the presence of TCPP shifts the energy of the surface states to higher values. The photoelectrochemical response of the unmodified and sensitized α -Fe2 O3 electrodes was followed by means of photovoltammetry and photocurrent-time transient techniques in a 0.1 M NaOHK+0.1 M KI solution under 25 mW/ cm2 white light illumination. The results showed that the photocurrent response exhibited by the TCPP-sensitized hematite films was 70% higher than the unmodified ones.
UR - http://www.scopus.com/inward/record.url?scp=77951165268&partnerID=8YFLogxK
U2 - 10.1149/1.3357257
DO - 10.1149/1.3357257
M3 - Article
AN - SCOPUS:77951165268
SN - 0013-4651
VL - 157
SP - D302-D308
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 5
ER -
