Design of poly(N-isopropylacrylamide) coated MnO2 nanoparticles for thermally regulated catalytic decomposition of H2O2

Abstract

We report the synthesis of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) coated manganese dioxide nanoparticles (PNIPAM@MnO₂ NPs) for the catalytic decomposition of hydrogen peroxide (H₂O₂), with the goal of developing a temperature-controlled catalytic system. For this purpose, we have developed MnO₂ NPs and further modified them with thermoresponsive PNIPAM containing nitrodopamine end groups. The modification of the MnO₂ NPs was confirmed using SEM, TEM, XPS, and TGA. Upon varying the temperature above and below the lower critical solution temperature (LCST) of the polymer coating, the NPs undergo spontaneous cyclic swelling–deswelling changes, as confirmed by DLS measurements. Photoluminescence (PL) experiments were performed to explore the catalytic decomposition of H₂O₂ by PNIPAM@MnO₂ NPs, indicating thermal control over the catalytic activity of the MnO₂ NPs. The proposed proof-of-concept of these smart PNIPAM@MnO₂ NPs for the decomposition of H₂O₂ may serve as a basis for the development of smart catalytic self-regulating systems in future work.