Hierarchical Ag3PO4@ZnIn2S4 nanoscoparium: An innovative Z-scheme photocatalyst for highly efficient and predictable tetracycline degradation

Abstract

Z-scheme photocatalyst preserved with superior oxidicability is an innovative photocatalyst system that can be used for efficient photocatalytic detoxification of antibiotics. In this study, Z-scheme Ag₃PO₄@ZnIn₂S₄ photocatalyst was constructed by decorating Ag₃PO₄ nanoparticles on ZnIn₂S₄ nanoscopariums. ZnIn₂S₄ nanoscopariums were prepared by self-templated strategy and given hierarchical structures. The hierarchical Ag₃PO₄@ZnIn₂S₄ provides more active sites for generating photogenerated carriers and large surface area for capturing tetracycline. The study results show that Ag₃PO₄@ZnIn₂S₄ performed excellently well in the photocatalytic degradation of tetracycline and also in protecting Ag₃PO₄ nanoparticles from photo-corrosion. The highest removal efficiency (up to 92.3%) was achieved from the optimal composites of Ag₃PO₄ and ZnIn₂S₄. In stability tests, Ag₃PO₄@ZnIn₂S₄ did not reduce the photocatalytic activity of degrading tetracycline after five successive runs. Active radical identification proves that the transfer behavior of electron and hole over Ag₃PO₄@ZnIn₂S₄ follows a direct Z-scheme mechanism. Furthermore, the transformation pathway for degrading tetracycline was proposed by combining the Fukui index prediction with Mass Spectra identification of intermediates. This work presents in-depth sights into a regulated degradation pathway from theoretical prediction and practical identification based on innovative Z-scheme photocatalyst.

Keywords: Fukui index; Hierarchitecture; Innovative Z-scheme photocatalyst; Self-templated; Tetracycline degradation.