Novel p-n-p heterojunction photocatalyst synthesized by BiFeO3, ZnO, and BiOBr nanoparticles: facile preparation and high photocatalytic activity under visible light

This work presents the preparation of novel ternary p-n-p BiFeO3/ZnO/BiOBr heterojunctions by the facile sol-gel method as novel visible-light-induced photocatalysts. The obtained photocatalysts were analyzed by XRD, EDX, FESEM, FTIR, DRS, BET, and PL techniques. The photocatalytic ability of the samples was evaluated by the degradation of different organic under visible light irradiation. The results showed that the weight percent of BiOBr and BiFeO(3)has a considerable effect on photodegradation ability of ternary nanocomposite such as the ZnO/BiFeO3/BiOBr (10:10) nanocomposite has the best photocatalytic activity in degradation of methylene blue (MB), rhodamine B (RhB), malachite green (MG), and congo red (CR), which was about 6.2, 19.1, 9.9, and 19.5-times as high as the pristine ZnO, respectively. The improved photoability was assigned to the more absorption of visible irradiation and the formation of p-n-p heterojunctions at the interface of p-BiFeO3, n-ZnO, and p-BiOBr semiconductors. The reactive species scavenging results predict that the(center dot)O(2)(-)and h(+)are the main involved species in RhB degradation. The photocatalytic activity of the optimum ternary photocatalyst did not obviously decrease after several cycles, suggesting that this sample is stable and it could be reutilized in successive cycles.