Enhanced photocatalytic removal of tetracycline by ZnO/NiCo2O4 through the construction of a p-n heterojunction.

[Display omitted] A new ZnO/NiCo 2 O 4 photocatalyst was synthesized to develop systems for removing pharmaceutical pollutants. Various properties of the synthesized nanocomposite such as crystal structure, morphology, optical activity, chemical composition, electrochemical functions, and energy band structure were investigated. The study on tetracycline removal showed that the catalytic activity of the ZnO/NiCo 2 O 4 nanocomposite (0.0426 min−1) is significantly higher compared to ZnO and NiCo 2 O 4 individually. Morphology images confirmed the creation of a heterojunction between rice-shaped ZnO and NiCo 2 O 4 nanoparticles. In photoluminescence and electrochemical impedance analyses, the nanocomposite displayed the weakest signal among its components, suggesting effective control of recombination and charge carrier transfer. The combination of NiCo 2 O 4 with ZnO resulted in increased light absorption in the visible spectrum, contributing to its photocatalytic performance. The energy band structure of ZnO and NiCo 2 O 4 was examined, presenting a detailed explanation of the most likely mechanism for the improved photocatalytic activity. [ABSTRACT FROM AUTHOR]