Assembling oxygen vacancy-enriched Co3O4/CeO2 nanozyme potential for wastewater analysis and treatment

Recently, nanozyme has found wide applications in various fields such as colorimetric sensors, biomedicine, and the environment. However, the development of highly active and multifunctional nanozyme remains a challenge. Herein, rod-shaped Co 3 O 4 /CeO 2 heterostructure nanozyme was fabricated through a two-step method comprising a hydrothermal and mechanical grinding process. This method enables efficient creating of well-defined nanocomposite interfaces, resulting abundant oxygen vacancies in the Co 3 O 4 /CeO 2 heterostructure, as evidenced by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy characterizations. Benefiting from the above characteristics, Co 3 O 4 /CeO 2 heterostructure exhibits peroxidase-mimicking activity and excellent catalytic performance. Therefore, a colorimetric sensor was constructed for the fast and sensitive quantitative analysis of tannic acid with good linearity in the range of 0.05–3.0 μM and a low detection limit of 29.8 nM. Furthermore, Co 3 O 4 /CeO 2 nanozyme also shows remarkable efficiency in degrading the pollutant rhodamine B, achieving nearly complete degradation within 20 min. The findings spotlight the potential of highly active nanozymes for environmental sensing and remediation applications, emphasizing the importance of interface engineering in heterogeneous nanostructures to enhance their catalytic performance.