Composite photocatalyst, tetragonal lead bismuth oxyiodide/bismuth oxyiodide/graphitic carbon nitride: Synthesis, characterization, and photocatalytic activity

Semiconductor photocatalysts that are robust and galvanized by visible light have been increasingly sought after, with lead bismuth oxyhalide (PbBiO₂X)-which constitutes a perovskite-like semiconductor-receiving vast attention recently. We noted, after a relevant literature survey, that tetragonal lead bismuth oxyiodide/bismuth oxyiodide/graphitic carbon nitride (t-PbBiO₂I/Bi₅O₇I/g-C₃N₄)-supported crystal violet (CV) dye photocatalytic degradation under irradiation with visible light has yet to be reported. The current study provides the report of t-PbBiO₂I/Bi₅O₇I/g-C₃N₄ composite isolation and characterization realized through field-emission scanning electron microscopy-energy-dispersive spectroscopy, X-ray diffraction, high-resolution X-ray photoelectron spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, Brunauer-Emmett-Teller analysis, Fourier-transform infrared spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy. Catalytic performance observation revealed that using t-PbBiO₂I/Bi₅O₇I/g-C₃N₄ resulted in an optimal reaction rate constant of 0.3518 h^-1, a derivation exceeding the derivations for the photocatalysts t-PbBiO₂I, Bi₅O₇I, g-C₃N₄, and t-PbBiO₂I/Bi₅O₇I by 15, 6.6, 13.1, and 1.4 times, respectively. As demonstrated by the quenching effects associated with diverse scavengers, the electron paramagnetic resonance results revealed reactive O₂^- to have a major role in the CV dye degradation. The paper proposes and also describes possible photodegradation mechanisms. The method that was realized in this study is valuable for PbBiO₂I/Bi₅O₇I/g-C₃N₄ synthesis and CV dye photocatalytic degradation for future applications in environmental pollution regulation.