Integration of Bi nanoparticles with brown TiO2 co-modified by Bi2Fe4O9 and BiFeO3: Double S-scheme photocatalysts towards degradation of pollutants

Recently, plasmonic photocatalysts fabricated using non-noble element of Bi have presented promising performances to tackle environmental and energy issues. Herein, we integrated Bi nanoparticles with brown TiO2 (denoted as TOX) co-modified by Bi2Fe4O9/BiFeO3 components to fabricate double S-scheme plasmonic photo- catalysts through a one-pot hydrothermal route. The results showed that the optimum TOX/Bi2Fe4O9/BiFeO3/Bi photocatalyst decomposed tetracycline about 36.1, 7.05, and 5.13 times superior than TOX, Bi2Fe4O9/BiFeO3, and TOX/Bi2Fe4O9/BiFeO3 samples, respectively. More importantly, the resulting plasmonic photocatalyst exhibited superior photodegradation activities against the removal of other antibiotics such as azithromycin and amoxicillin, and dyes such as methylene blue, malachite green, and rhodamine B upon visible light. The extraordinary performance of rationally designed plasmonic photocatalyst was devoted to more harnessing of visible light and boosting charge segregation among the components facilitated by double S-scheme heterojunctions. The scavenging studies exhibited the formation of center dot OH, center dot O2-, and h+ reactive species over TOX/ Bi2Fe4O9/BiFeO3/Bi nanocomposite under visible light. Considering the high stability, facile fabrication procedure, excellent biocompatibility, and impressive performance of TOX/Bi2Fe4O9/BiFeO3/Bi photocatalyst in destroying a wide range of contaminants in water, it is inferred that other impressive plasmonic photocatalystsbased on Bi can be designed and developed for effectively addressing the environmental issues upon visible light.