Construction of a thermo-responsive polymer brush decorated Fe3O4@catechol-formaldehyde resin core–shell nanosphere stabilized carbon dots/PdNP nanohybrid and its application as an efficient catalyst

Abstract

In recent years, there has been growing interest in the catalytic properties of noble metal nanoparticles (NMNs) with a high surface area and activity. However, the instability and easy self-aggregation of NMNs limit their broad application in catalysis. The integration of polymers into a catalyst system is advantageous for improving the surface properties of the catalyst support and the stability of NMNs, which is expected to solve the above problem. Herein, we successfully constructed well-dispersed carbon dot (CD) decorated Pd nanoparticles supported on thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) brush functionalized mussel-inspired Fe₃O₄@catechol formaldehyde resin (CFR) core–shell magnetic nanospheres. Different molecular weights of sulfhydryl-terminated PNIPAM polymers grafted onto the Fe₃O₄@CFR nanospheres can affect the morphology and catalytic activity of the designed Fe₃O₄@CFR-S-PNIPAM@Pd/CD nanohybrids. The as-prepared nanohybrids as catalysts exhibited high catalytic reduction activity because of the synergistic effect of different components with easy separation and recycling stability. The magnetic Pd-based nanocatalyst revealed excellent catalytic efficiency for the Knoevenagel condensation and Suzuki cross-coupling reactions. Additionally, the PNIPAM functionalized nanocatalyst also showed interesting temperature-responsive behavior in the catalytic process. This work has a guiding significance for the design and fabrication of functional nanohybrid materials with a controllable structure and chemical composition for industrial catalysis.