Eosin Y sensitized BiPO4 nanorods for bi-functionally enhanced visible-light-driven photocatalysis

Abstract

In this work, we report a novel photocatalyst of Eosin Y dye sensitized BiPO₄ nanorods via a low-temperature and impregnation adsorption method. It shows enhanced visible-light-driven photocatalytic activity for degrading methylene blue (MB) and 2,4-DCP compared to that of pristine BiPO₄ nanorods. The mass ratio of Eosin Y/BiPO₄ is varied from 5 wt% to 30 wt% and the optimum value is 15 wt%, showing 46.7 and 10.5 fold greater apparent reaction rates than pristine BiPO₄. Moreover, all of the reduced MB was transformed into CO₂ and H₂O during the photocatalysis, showing the good mineralization ability (almost 100%) of the composite. Furthermore, the photocatalytic mechanism of the composite is also investigated here by the zeta potential, scavenger experiments, Electron Paramagnetic Resonance (EPR), Photoluminescence Spectroscopy (PL), and a series of electrochemical analyses. The results show that (i) e⁻ is the main reactive species and (ii) Eosin Y coated and adsorbed on BiPO₄, thus widening the response range to the visible light region and accelerating the charge separation/transfer, resulting in bi-functionally promoted activity.