Attapulgite Doped with Fe and Cu Nanooxides as Peroxidase Nanozymes for Antibacterial Coatings

The search for low-cost, highly efficient, and stable nanozymes mimicking peroxidase (POD) enzymes remains a great challenge in the development of valuable antibacterial applications. Herein, a natural attapulgite (ATP)-supported Fe and Cu oxide with mixed valences (Fe-Cu/ATP) is reported as an efficient nanozyme by a feasible impregnation method. The obtained Fe-Cu/ATP nanozyme with a large specific area and high dispersity can effectively catalyze the hydrogen peroxide (H2O2) decomposition, exhibiting enhanced POD-like activity compared with Fe/ATP, Cu/ATP, and pristine ATP. In addition, the Fe-Cu/ATP showed high stability and reusability. Through further combination with the density functional theory calculation, the electron density of the ATP surface is increased by simultaneously introducing Fe and Cu dopants. Thus, Fe-Cu/ATP possesses excellent antibacterial properties including a short-time effect depending on the POD-like activity with H2O2 and a long-term effect generated by the metal without H2O2. Finally, a coating desktop and an antibacterial fabric were delicately designed and fabricated by loading Fe-Cu/ATP onto polyethylene and a fabric surface, showing the enormous potential of Fe-Cu/ATP as building and medical functional coatings. This study provides a rational way to design natural mineral nanozymes for promising antibacterial applications.