Facile synthesis of Z-scheme Bi2O3/Bi2WO6 composite for highly effective visible-light-driven photocatalytic degradation of nitrobenzene

In this paper, nitrobenzene was found to be efficiently degraded by the as-prepared Z-scheme Bi2O3/Bi2WO6 photocatalyst under visible light. The Bi2WO6 and the composites were fabricated individually by solid phase synthesis and water-assisted grinding method. The crystal structure, morphologies, interface, optical property and Brunauer-Emmett-Teller (BET) surface area of samples were examined by different characterization techniques. The tests on photodegradation of nitrobenzene stated clearly the as-prepared composite exhibited evidently enhanced photocatalytic performace compared with uniphase material. Additionally, the optimal Bi2O3 content in the coupled photocatalysts was 2%. The supreme rate constant of nitrobenzene degradation was almost 3.1 and 2.7 times that of single Bi2O3 and Bi2WO6 , respectively. The obviously increased photocatalytic performance of the composite was due to the highly effective separation of photoexcited electron-hole pairs over the Z-scheme structure formed between Bi2O3 and Bi2WO6. The investigation provides great potential applications in treatment of the toxic and refractory wastewater.