Resumo (PT):
Abstract (EN):
A photoelectrochemical (PEC) device capable of splitting water into storable hydrogen fuel by the direct
use of solar energy is becoming a very attractive technology since it is clean and sustainable. Indeed, real
field experiments are being developed in order to assess technological issues for large-scale usage under
outdoor conditions. Following the need for developing photoelectrochemical devices with an optimized
design that allows reaching a commercial performance level, the present works describes an innovative
PEC cell for testing different photoelectrodes configurations, suitable for continuous operation and for
easily collect the evolved gases. Moreover, a porous Teflons diaphragm useable for a wide range of
aqueous electrolyte solutions is tested. Two semiconductors were investigated: tungsten trioxide and
undoped hematite. The WO3 photoelectrodes were deposited in two different substrates: (i) anodized
WO3 photoelectrodes on a metal substrate and (ii) WO3 deposited by blade spreading method on a TCO
glass substrate. The undoped-Fe2O3 photoanode was deposited by ultrasonic spray pyrolysis technique
in a TCO glass substrate. The material deposited on glass substrates allows to obtain transparent
photoelectrodes. Photocurrent–voltage characteristics were obtained for all samples characterized under
three different conditions: (i) no membrane separating the anode and the cathode evolution; (ii) using a
Teflons diaphragm and (iii) using a Nafions 212 membrane. The transparent samples (photoanodes
deposited on glass substrates) produced the highest values of photocurrent when the Teflons
diaphragm was used. This photocurrent enhancement was assigned to the high reflectance showed by
the diaphragm, which reflects back a significant fraction of the transmitted solar radiation.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Notas:
Publicação abrangida pelo Journal Citation Reports 2015
Nº de páginas:
12