Characterization and photocatalysis of visible light driven Z-scheme Bi2WO6/Bi2MoO6 heterojunction for Rhodamine B degradation

Efficient visible light sensitive semiconductors are instrumental for the effective dye degradation for the decontamination of water. Thus, the novel visible light driven photocatalysts of (1-x)Bi2WO6-xBi2MoO6 (where x = 0.05, 0.10, 0.15 and 0.20 wt%) heterostructures were synthesized using one-pot hydrothermal method. The samples were thoroughly characterized by XRD, FESEM, XPS, UV–vis DRS, FTIR and photoluminescence (PL), respectively to identify phase purity, morphology, oxidation states, optical band gap, vibrational groups and charge recombination. The photodegradation studies carried out on Rhodamine B dye by these heterostructures under visible light displayed that 0.90Bi2WO6/0.10Bi2MoO6 heterostructure exhibited the optimum degradation for 4 hrs than that of Bi2WO6 and Bi2MoO6. The interplay between the optical band gaps and the redox potentials of Bi2WO6 and Bi2MoO6 endowed these heterostructures for the effective charge separation resulting in the active participation for the adequate photodegradation. The results of scavenger's data affirmed that ∙O2- and h+ radicals played superior role comparably with OH∙ radicals for dye degradation. The charge accumulation via Z-scheme formed between Bi2WO6 and Bi2MoO6 heterojunction causes these heterostructures to exhibit the improved PCA.