Nanozymes are next-generation of nanomaterials with enzyme-like activities. In particular, nanozymes with peroxidase (POD)-like activity have been utilized in various fields, including antibacterial, detection, degradation, etc. However, their extensive applications were limited by their low catalytic activity currently. Herein, we have presented a composite nanozyme based on attapulgite (ATP) (Fe-ATP-MoS₂ (FAM)), which exhibited enhanced POD-like activity (185.33 U·mg⁻¹), 4.25 times higher than that of Fe-MoS₂ (FM) (43.63 U·mg⁻¹). The density functional theory (DFT) calculations indicated that the addition of ATP increased the electron density of metal centers (Mo and Fe). More importantly, Michaelis–Menten kinetics revealed that the introduction of ATP significantly enhanced the binding affinities of substrates through the pores of ATP, forming a highly concentrated substrate microenvironment and thus promoting its POD-like activity. Additionally, from molecular size and kinetic analysis, we proposed that the changes in substrate size before and after oxidation also significantly affected its Michaelis-constant (K_m) value. Furthermore, we utilized FAM in the applications of highly effective antibacterial application and sensitive detection of glutathione (GSH). In conclusion, this work provides a novel approach for designing a highly efficient nanozyme based on natural mineral composites.

Light-drive hydrogen production using titanium-based perovskite is one sustainable way to reduce current reliance on fossil fuels, but its wide applications are still limited by high electron−hole recombination and sluggish surface reaction. Thus, the developments for low-cost and highly efficient co-catalysts remain urgent. Inspired by natural [NiFe]-hydrogenase active center structure, a hydrogenase-mimic, NiCo₂S₄ nanozyme was synthesized, and subsequently decorated onto the CaTiO₃ to catalyze the hydrogen evolution reaction (HER). Among the following test, CaTiO₃ with a 15% loading of NiCo₂S₄ nanozyme exhibited the highest HER rate of 307.76 μmol·g^–1·h^–1, which is 60 times higher than that of the CaTiO₃ alone. The results reveal that NiCo₂S₄ not only significantly increased the charge separation efficiency of the photogenerated carriers, but also substantively lowered the HER activation energy. Mechanism studies show that NiCo₂S₄ readily splits H₂O by forming the Ni(OH)-Co intermediate and only Ni in the bimetallic center alters the oxidation state during the HER process in a manner analogous to the [NiFe]-hydrogenase. In contrast to the often-expensive synthetic catalysts that rely on rare elements such as ruthenium and platinum, this study shows a promising way to develop the nature-inspired cocatalysts to enhance the photocatalysts’ HER performance.

Rational design of metallic active sites and its microenvironment is critical for constructing superoxide dismutase (SOD) nanozymes. Here, we reported a novel SOD nanozyme design, with employing graphene oxide (GO) as the framework, and δ-MnO₂ as the active sites, to mimic the natural Mn-SOD. This MnO₂@GO nanozyme exhibited multiscale laminated structures with honeycomb-like morphology, providing highly specific surface area for ·O₂⁻ adsorption and confined spaces for subsequent catalytic reactions. Thus, the nanozyme achieved superlative SOD-like catalytic performance with inhibition rate of 95.5%, which is 222.6% and 1605.4% amplification over GO and MnO₂ nanoparticles, respectively. Additionally, such unique hierarchical structural design endows MnO₂@GO with catalytic specificity, which was not present in the individual component (GO or MnO₂). This multiscale structural design provides new strategies for developing highly active and specific SOD nanozymes.