Space-confined growth of two-dimensional manganese oxide nanosheets in plant-cell structures for efficient tetracycline degradation

Abstract

Manganese oxides (MnxOy) stand out as promising candidates for various redox reaction involved applications due to their diverse valence states. The expansive surface area of two-dimensional (2D) materials offers an abundance of active sites for reactions, thereby gathering significant interest for catalytic applications. Nonetheless, facile synthesis of 2D nano metal oxides remains a challenge. In this study, cabbage leaf cells were employed as bio-scaffolds to fabricate 2D MnxOy nanomaterials, leveraging the confined space within the cells. The resulting 2D MnxOy nanosheets, featured by multiple valence states and composed of Mn2O3 and Mn3O4 nanocrystals, exhibit a planar size of 32 nm and a lamellar thickness of about 3.95 nm. The distinctive 2D structure, coupled with the material’s multivalent manganese, facilitates efficient electron transfer, enhancing its function as a hetero-catalyst. Consequently, 2D MnxOy nanosheets demonstrate remarkable efficiency, achieving an 89 % removal of tetracycline (40 mg·L–1) with the assistance of H2O2. This study paves the way for employing biological templates to meticulously synthesize nanomaterials with precise morphologies, with applications extending across various fields.