Abstract (EN):
A phenomenological model is proposed for a better understanding of the basic mechanisms
of photoelectrochemical (PEC) cells. The main assumptions of the one-dimensional
transient phenomenological model are: i) bulk recombination of the conduction band
electrons with holes in the valence band; ii) the mobile charge transport takes place via
diffusion, which arises from the concentration profiles, and migration, caused by
a macroscopic electric field; iii) negligible effects of microscopic electric fields in the cell
and screening effects, as well as negligible Helmholtz and diffuse layers. For modeling
purposes, the photoanode was assumed to be a homogeneous nanocrystalline hematite
structure, with thickness L, porosity 3p and tortuosity s. The TCO/semiconductor interface
was modeled as an ideal ohmic contact, while the electrolyte/platinized TCO interface was
described by a ButlereVolmer approach. An alkaline electrolyte solution was used,
allowing the transport of the ionic species from the counter-electrode to the photoanode.
The continuity and transport governing equations are defined for the mobile species
involved: electrons in the conduction band of the semiconductor, holes in the valence band
and hydroxyl ions in the electrolyte. Simulated IeV characteristics were computed and the
corresponding results compared with the experimental values. The simulated results were
in straight agreement with the experimental data.
Language:
English
Type (Professor's evaluation):
Scientific
Notes:
Publicação abrangida pelo Journal Citation Reports 2015
No. of pages:
14