Bi(2)O(3) and g-C(3)N(4) quantum dot modified anatase TiO(2) heterojunction system for degradation of dyes under sunlight irradiation

A facile and feasible method was successfully utilized to incorporate Bi(2)O(3) and g-C(3)N(4) quantum dots on TiO(2) surface to synthesize a novel composite g-C(3)N(4)/TiO(2)/Bi(2)O(3). The photocatalytic activity of the composite g-C(3)N(4)/TiO(2)/Bi(2)O(3) for degradation of dyes under sunlight and UV light irradiation was evaluated. It possessed the higher photocatalytic performance than that of pristine TiO(2) or g-C(3)N(4) under the same conditions. Under sunlight irradiation, the reaction rate constants of the g-C(3)N(4)/TiO(2)/Bi(2)O(3) was about 4.2 times and 3.3 times higher than that of TiO(2) and g-C(3)N(4), respectively. The promising photocatalytic performance was attributed to the broader light absorption range and efficient separation of photoinduced carriers. Moreover, based on the TEM, XPS, XRD, UV-vis spectrum, radicals scavenging test and Mott–Schottky analysis systematic mechanism for photodegradation process was proposed. This work provides a promising strategy for the modification of TiO(2)-based semiconductors by incorporating different quantum dots and promoting the efficiency of the photocatalysts in practical application.