Photoelectrodes with titanate nanotubes sensitized by mesoporphyrin
derivative from cashew nut shell
MATERIA-RIO DE JANEIRO, (2019)DOI: 10.1590/S1517-707620190001.0650
Abstract
Titanate nanotubes (TiNTs) with the chemical composition Na2Ti3O7 center
dot nH(2)O (NaTiNT) were obtained through a hydrothermal method in
highly alkaline medium. Protonated titanates nanotubes (H-TiNTs), with
the composition Na2Ti3O7 center dot nH(2)O, were prepared by ion
exchange reaction through a suspension of Na2Ti3O7 center dot nH(2)O
nanotubes in HCl medium, promoting the exchange of Na+ ions by H+. Both
Na2Ti3O7 center dot nH(2)O and H2Ti3O7 center dot nH(2)O products, as
well the TiO2 used as raw material for the nanotubes processing, were
used as starting material for the solar cells photoelectrodes sensitized
using mesoporphyrin extracted from a precursor of cashew nut shell.
Exposing the NaTiNT sample to solar radiation of 1258 W/m(2), a
short-circuit current density (I-SC) of 13 mu A/cm(2) and an
open-circuit voltage (V-OC) of 370 mV were registered and, a current
density of 7.6 mu A/cm(2) and a voltage of 256 mV for the prototype cell
based on H-TiNTs. A current density of 1.1 mu A/cm(2) and an
open-circuit voltage of 1.6 mV were obtained for the cell using TiO2 as
electrode.