Reconciling Nanozyme Catalytic Activity with Seawater pH via Doping Regulation for Marine Antifouling

Marine biofouling imposes substantial energy and maintenance penalties on ships and offshore infrastructure. Peroxidase (POD)-like nanozymes offer a catalytic antifouling route but are constrained by optimal activity under acidic conditions incompatible with seawater pH. Here, a doping-regulated nanozyme design strategy is proposed to overcome this activity–environment incompatibility. Cerium is introduced into the Ru/C framework to modulate the electronic structure of the active sites, enabling effective POD-like activity under neutral conditions. The resulting nanozyme (CeRuC) is incorporated into a low-surface-energy coating to construct a multifunctional antifouling system integrating catalytic sterilization with fouling-release behavior. CeRuC nanozyme exhibits antibacterial efficiencies exceeding 98%, and the composite coating inhibits diatom adhesion by over 98%, as well as antifouling efficiency of ∼90% after 60 days of natural seawater immersion, compared with only ∼20% for the nanozyme-free counterpart. This work establishes a general engineering strategy for reconciling nanozyme catalytic activity with marine environmental conditions and provides guidance for environmentally compatible antifouling coating design.