3D defect-enriched Cu/Cu2O–Al2O3 zigzag nanostructures for efficient degradation of tetracycline antibiotics

Abstract

Researching photocatalysts that make full use of sunlight is of great significance for the efficient and environmentally friendly removal of existing toxic and harmful pollutants. Here, defect-enriched Cu/Cu₂O–Al₂O₃ nanoribbons with zigzag edges were successfully prepared and used to degrade tetracycline antibiotics (TCs). The design of the defect-enriched zigzag structure and the metal–semiconductor composition enable them to promote not only the separation of photogenerated carriers, but also the adsorption of oxygen to generate reactive oxygen species (ROSs). Meanwhile, density functional theory (DFT) calculations validate that the Cu/Cu₂O structures with oxygen vacancies (OVs) exhibit the best oxygen adsorption and capture ability. The obtained catalyst exhibits a superior degradation efficiency on TCs (e.g., up to 99.2% degradation of TC in 6 min with 0.556 min⁻¹ of kinetic constant k) and excellent catalytic degradation stability. In addition, the possible degradation pathways, the main species of ROSs and the synergistic mechanism of the photocatalytic system were systematically studied. This study provides an environmentally friendly way to treat antibiotic pollution directly by visible light.