Construction of thermo-responsive copolymer stabilized Fe3O4@CDs@PdNPs hybrid and its application in catalytic reduction

A novel and convenient method for fabricating homogeneous nanocatalysts with high catalytic activity and controllable reusability are promising for catalytic reduction. In this work, a high-efficiency magnetic recyclable nanocatalyst (PFe3O4@CDs@PdNPs) was successfully prepared via depositing highly dispersed palladium nanoparticles (Pd NPs) on the support of thermo-responsive copolymer functionalized superparamagnetic Fe3O4 nanoparticles (NPs) with carbon dots (CDs) as both stabilizing and reducing agent. The thermo-responsive copolymers with catechol end groups could be facilely anchored onto Fe3O4 NPs (PFe3O4) through mussel-inspired chemistry strategy. The well-dispersed ultrafine Pd NPs were located on copolymer brushes decorated Fe3O4 NPs using the episulfide ligand-containing copolymer as the costabilizer. Fourier transform infrared, thermogravimetric analysis and other tests proved that the copolymer brushs were successfully grafted on the surface of Fe3O4 NPs. Moreover, the transmission electron microscopy and X-ray photoelectron spectroscopy confirmed the presence of CDs in nanohybrids. In addition, the PFe3O4@CDs@PdNPs showed interesting thermo-responsive catalytic behaviour because of the presence of thermo-responsive polymer chains onto the catalyst surface. Finally, owing to the good water dispersibility and synergistic effect of Pd NPs with CDs, the PFe3O4@CDs@PdNPs nanocatalyst possessed higher catalytic activity for the catalytic reduction of different dyes and nitrophenols as compared with PdNPs@PFe3O4 without CDs modification.