Water-Soluble Phosphaviologens for Effective Photoinduced Charge Separation

Two highly water-soluble phosphaviologens
were synthesized via
effective protocols requiring as little as two steps and only minimal
purification. The new species were purposefully designed for potential
application in photocatalysis as a binary system in conjunction with
titanium dioxide (anatase). To this end, the efficacy of the new materials
for effective charge separation was investigated via photodegradation
of methylene blue. In addition to improved aqueous solubility of the
phosphaviologens, we successfully inhibited the photodegradation of
methylene blue in comparison to pristine TiO2 due to the
highly electron accepting properties of phosphaviologens, which can
effectively accept a photoexcited electron from TiO2. We
also went on to compare our phosphaviologens to traditional viologens,
revealing that they are equally as effective in creating a charge-separated
state for TiO2.