One-step in-situ construction of efficient solar light-driven dual Z-scheme nanocomposite with specific nanoparticle arrangement for antibiotic degradation: Strategy, performance, and mechanism insights

Abstract

Ternary dual Z-scheme photocatalysts prepared using conventional methods may cause photocatalyst nanoparticles with distinct interfaces and limited effective dual Z-scheme structures, which are unfavorable for the transfer of electrons among Z-scheme nanoparticles. In this study, a ternary dual Z-scheme CuO/CuBi₂O₄/Bi₂O₃ nanocomposite was constructed in-situ based on incomplete solid-phase chemical reactions, and applied to norfloxacin (NFX) degradation. The CuO/CuBi₂O₄/Bi₂O₃ photocatalyst prepared in one step has fuzzy interfaces and a specific nanoparticle arrangement, with CuBi₂O₄ located between CuO and Bi₂O₃ nanoparticles, which can form an effective dual Z-scheme photocatalytic system. The results showed that the degradation extent of NFX (5.0 mg/L) using CuO/CuBi₂O₄/Bi₂O₃ can reach 82.40 % within 240 min at 1.0: 1.0 M ratio of Cu(OH)₂ and Bi(OH)₃. The rate constant of 0.0052 min⁻¹ using CuO/CuBi₂O₄/Bi₂O₃ nanocomposite is 2.17, 1.63, and 7.43 times higher than that of the CuO, Bi₂O₃, and CuBi₂O₄, respectively. The generation of h⁺, •OH, and •O₂⁻ was demonstrated during the degradation process. Additionally, the CuO/CuBi₂O₄/Bi₂O₃ nanocomposite photocatalyst exhibited high stability after four cycles and can degrade other antibiotics and dyes, such as tetracycline, crystal violet, acridine orange, and acid red B. Furthermore, the pathways and possible mechanisms for NFX degradation were proposed. This technology provides strategies for preparing ternary photocatalysts with specific nanoparticle arrangements and treating organic pollutants in water using sunlight.