Light-Driven Self-Cascade Peroxidase-like Nanozymes without Exogenous H₂O₂

The peroxidase (POD)-like nanozyme typically requires the addition of exogenous H2O2. To address the limitation, previous work mainly adopted a cascade strategy for H2O2 production. Herein, we propose a new light-driven self-cascade strategy to construct POD-like nanozymes without exogenous H2O2. The model nanozyme resorcinol–formaldehyde resin-Fe3+ (RF-Fe3+) is synthesized with the hydroxyl-rich photocatalytic material RF as the carrier to in situ chelate metal oxides, which can simultaneously achieve the functions of in situ H2O2 generation under irradiation and substrate oxidation via POD-like behavior. Notably, RF-Fe3+ exhibits high affinity to H2O2, attributed to the excellent adsorption ability and hydroxyl-rich feature of RF. Furthermore, the dual photoelectrode-assisted photofuel cell was further constructed with a high-power density of 120 ± 5 μW cm–2 based on the RF-Fe3+ photocathode. This work not only demonstrates the new self-cascade strategy of in situ generation of catalysis substrates but also provides an opportunity to extend the catalytical field