Self-Assembled Magnetic Pt Nanocomposites for the Catalytic Reduction of Nitrophenol

Self-assembled nanotechnology has been used widely in various well-defined microstructures fabrication. Herein, this synthetic protocol was successfully utilized to in situ or hierarchically prepare magnetic Pt nanocomposites Fe3O4@Pt via a distinguishing two-step process. The distinction of these two pathways is due to the different synthetic processes. In the case of in situ preparation (Path I), it involves a supramolecular self-assembly of boron clusters with γ-CD on Fe3O4 substrate and then followed by in situ formation of Pt nanoparticles (NPs). But in the case of hierarchical preparation (Path II), the first step is preparing Pt NPs colloids reduced by boron clusters Cs2[closo-B12H12], and subsequent step is immobilizing the as-prepared [closo-B12H12]2–-capped Pt NPs on the Fe3O4@γ-CD. The success of these two fabrication strategies lies in the use of trifunctional boron clusters (reductant, stabilizer, and superchaotropic anchor). Both of the as-prepared Fe3O4@Pt nanocomposites showed good catalytic performance in the selective nitro-group reduction of nitroaromatics. A control test further indicated that the in situ prepared Fe3O4@Pt nanocomposites, with smaller size and higher loading of Pt NPs, exhibited a better catalytic performance and recyclability.