Mussel-inspired preparation of temperature-responsive polymer brushes modified layered double hydroxides@Pd/carbon dots hybrid for catalytic applications

A novel type of multicomponent nanocomposite of LDH@PDA@PNIPAM@Pd/carbon dots (CDs) was successfully constructed for highly efficient heterogeneous catalytic reduction from two-dimensional layer double hydroxide (LDH) nanosheet functionalized with thermo-responsive PNIPAM polymer brushes based on the mussel-inspired chemistry. CDs were used as a reductant and stabilizer by in situ loading metal Pd onto LDH@PDA@PNIPAM. Compared with LDH@PDA@PNIPAM@Pd catalyst without CDs modification, the designed LDH@PDA@PNIPAM@Pd/CDs nanohybrid catalyst had better catalytic reduction ability for various dyes and nitrophenol thanks to the synergistic catalytic effect between metal active center and CDs, LDH and their high dispersion stability. Especially, a good catalytic reduction activity was demonstrated for methylene blue (MB) with a high TOF (545.2 min(-1)). Furthermore, the nanohybrid presented interesting thermo-responsive catalytic property due to the existence of PNIPAM polymer chains. In addition, the prepared catalyst also exhibited outstanding catalytic property for the Knoevenagel condensation reaction. Our study provides a new way for the composite preparation of organic-inorganic hybrid materials by polymer and inorganic materials, and shows great potential in the field of catalytic applications.