Although Prussian blue nanozymes (PBNZ) are widely applied in various fields, their catalytic mechanisms remain elusive. Here, we investigate the long-term catalytic performance of PBNZ as peroxidase (POD) and catalase (CAT) mimetics to elucidate their lifespan and underlying mechanisms. Unlike our previously reported Fe 3 O 4 nanozymes, which exhibit depletable POD-like activity, the POD and CAT-like activities of PBNZ not only persist but slightly enhance over prolonged catalysis. We demonstrate that the irreversible oxidation of PBNZ significantly promotes catalysis, leading to self-increasing catalytic activities. The catalytic process of the pre-oxidized PBNZ can be initiated through either the conduction band pathway or the valence band pathway. In summary, we reveal that PBNZ follows a dual-path electron transfer mechanism during the POD and CAT-like catalysis, offering the advantage of a long service life.
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.
危险品化学品经营许可证（带存储）