Cascade charge separation mechanism by ternary heterostructured BiPO4/TiO2/g-C3N4 photocatalyst

A complex ternary BiPO/TiO/gCN heterostructure has been obtained from a simple impregnation method having good photoactivities for the degradation of phenol under solar-like irradiation. From the wide structural, surface and electronic characterization, we have stated that the formation of the ternary heterojunction notably affect photoactivity of pristine TiO. Thus, the best result for the binary system was obtained for 70wt% TiO-30wt% BiPO system. The incorporation of gCN leads to a further improvement on the photocatalytic activity when it is specifically done over TiO. By means of photoluminescence spectroscopy and reactive oxygen species formation test, we propose that the effective charge carrier separation is taking place through a cascade-driven electronic mechanism. Therefore, by choosing the adequate band-engineering tailoring an important improved photoactivity can be achieved.S. Obregón also thanks CSIC for the concession of a JAE-Pre grant. The financial support by projects P09-FQM-4570 and ENE2011-24412 is fully acknowledged