Synergetic effect of Bi2WO6 photocatalyst with C60 and enhanced photoactivity under visible irradiation.

Fullerene (C60)-modified Bi2WO6 photocatalyst is prepared by a simple absorbing process. The as-prepared samples show the high efficiency for the degradation of nonbiodegradable azodyes methylene blue (MB) and rhodamine B (RhB) under visible light (lamda >420 nm) and simulated solar light (lamda >290 nm). After being modified by C60, the photocatalytic activities of Bi2WO6 samples increase about 5.0 and 1.5 times for the degradation of MB and RhB under visible light irradiation, whereas 4.6 and 2.1 times under xenon lamp irradiation, respectively. The enhanced photocatalytic activity for C60-modified Bi2WO6 comes from the high migration efficiency of photoinduced electrons on the interface of C60 and Bi2WO6 which is produced by the interaction of Bi2WO6 and C60 with the conjugative pi-system. The optimum synergetic effect is found at a weight ratio of 1.25 wt % (C60/Bi2WO6). The photocatalytic reaction process of C60-modified Bi2WO6 is mainly governed by direct holes and O2*- oxidation.