Abstract:
In 1991, Michael Grätzel and co-workers developed a new photovoltaic cell known as
Dye Sensitized solar cells (DSSCs); these photovoltaic semiconductor devices convert
solar radiation directly into electricity [1]. Metal-free sensitizers such as organic dyes
and natural dyes have received attention as alternative DSSC applications and have
been extensively developed [2]. Two metal free dyes were reported. These dyes were
prepared through Schiff base synthetic methods, which are easy to follow. The dyes absorb light in the visible light region. The interaction with ionic other
species (sensing) properties were studied, with dye I1 (sensor A) and dye I2 (sensor
B) designations. These recognition properties towards various ions were investigated
firstly by naked eye observation and secondly by spectroscopic methods such as UVvis in water-soluble DMSO. As a result, the addition of mercury (Hg2+) to sensor A
displayed a clearly visible “naked eye” detectable colorimetric activities (from yellow
to pale yellow), while the addition of fluoride (F-) and cyanide (CN-) to sensor B also
displayed "naked eye" detectable colorimetric activities (from pink to purple), in
DMSO at ambient temperature. Thus each dye possesses a duality function, as an
organic DSSC as well as a colorimetric sensors for discriminating specific ionic
species in a given environment.