Graphitic carbon nitride loaded Bi\(_{4}\)O\(_{5}\)I\(_{2}\) for elevated photocatalytic tetracycline degradation

As a robust photocatalyst, Bi4O5I2 have has attracted significant scientific interest owing to its narrow bandgap energy, escalated electronic properties and high stability. Nonetheless, the unfavourable band structure and higher recombination of excitons have restricted its diversified photocatalytic applications. In this context, binary heterojunction construction using Bi4O5I2 could be considered an effective strategy for spatial charge carrier separation across the hetero-interface, leading to an enhanced activity. In this study, we have prepared Bi4O5I2/g-C3N4 Z-scheme hetero-structures via a wet impregnation strategy that preserves the spherical structure of Bi4O5I2. The phase purity, chemical bonding, morphology and microstructure of the composite were confirmed using XRD, FTIR, SEM, TEM and HRTEM studies. The formation of robust 3D-2D contact junction triggers the charge separation and migration at the hetero-interface. Furthermore, the Z-scheme charge transfer dynamics helps to retain the redox ability of the excitons. As a result, The Bi4O5I2/g-C3N4 heterojunction composite exhibited 84.6% of tetracycline degradation within 60 min that is 1.8 and 2.7 folds higher than pristine Bi4O5I2 and g-C3N4, respectively. The findings of this study have major implications for building highly effective heterojunctions for upgraded photocatalytic applications.