A pine cone-like SnO2/Bi2O2CO3 Z-scheme heterojunction photocatalyst enhances the photocatalytic degradation of tetracycline.

The widespread presence of antibiotic residues, such as tetracycline (TC), in natural water bodies poses a threat to ecosystems and human health. Developing photocatalysts capable of efficient and rapid separation of photogenerated charge carriers under ambient conditions with visible light irradiation offers an eco-friendly solution for mineralizing persistent organic pollutants. In this study, we designed and synthesized a novel pine cone-like SnO2/Bi2O2CO3 (SBC) Z-scheme heterojunction photocatalyst via a solvothermal method to enhance the degradation efficiency of TC in water. Comprehensive characterization via X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed successful heterojunction formation and revealed unique interfacial electronic properties. Photocatalytic experiments demonstrated that the SBC heterojunction significantly outperformed the individual components in degrading TC, achieving a TC removal efficiency of 81% after 70 min. This enhancement is attributed to the efficient separation and transfer of photogenerated charge carriers facilitated by the Z-scheme heterojunction structure.