A comparative photocatalytic study of 2D bismuth-based photocatalysts

Utilizing bismuth-based perovskites in photocatalytic degradation presents a topical issue. However, there are controversies regarding the optimal bismuth-based catalyst for providing efficient degradation rate. This study aims at comparing RhB degradation using two bismuth-based catalysts, namely Cs₃Bi₂Br₉ and Bi2O3. Both catalysts were duly synthesized and characterized. The morphology of the two catalysts possessed 2D nanosheets, with those of Cs₃Bi₂Br₉ being larger and more closely stacked. UV-Vis DRS results proved that the ability of Bi2O3 to absorb visible light was higher than that of Cs₃Bi₂Br₉. The band gap energy was 2.54 eV and 2.45 eV for Cs₃Bi₂Br₉ and Bi2O3, respectively. Further, both catalysts achieved good degradation efficiency in removing RhB within 150 min though Bi2O3 (~96%) attained a slightly higher percentage than Cs₃Bi₂Br₉ (~92%) due to the presence of 2D nanosheets. The present study highlights the significance of bismuth-based photocatalysts with 2D nanosheet morphology in boosting the photocatalytic degradation of RhB.