Exploring the Long‐term Catalytic Mechanism of Catalase‐Like Nanozymes Prepared by Flow Chemistry

Despite of the rapid development of nanozymology, the long‐term catalysis of nanozymes, which reflects their hidden catalytic mechanism and sustainability is still overlooked. Herein, we systematically investigate the prolonged catalase (CAT)‐like activity of nanozymes prepared by flow chemistry. Through a rational control on the reaction conditions in micro‐channel, fast synthesis of a library of common CAT‐like nanozymes, including Prussian blue (PB), manganese Prussian blue (Mn‐PB), Fe 3 O 4 , CeO 2 , Pt, and Au is realized. The mass production capability of the developed synthetic device is validated with a high yield of 60.5 g uniform PB nanozymes in 115 min. A precise definition of s nano value is then proposed, quantitively expressing the long‐term catalytic behavior of the as‐prepared nanozymes with self‐increasing or self‐depleting activity. Taking Mn‐PB, Fe 3 O 4, and Pt as representative models, the irreversible oxidation effect of H 2 O 2 is demonstrated to endow them with abundant oxygenated groups during the prolonged catalysis and regulate their reaction energy profiles, thus varying their catalytic activities. Our results reveal the superiority of flow synthesis for the nanozymes preparation and the guiding significance of long‐term catalysis for the mechanism study and the efficient application of nanozymes.