Insitu growth of Rh nanoparticles with controlled sizes and dispersions on the cross-linked PVA–PEI nanofibers and their electrocatalytic properties towards H2O2

Abstract

A facile approach for the synthesis of uniform, small size and well-dispersed rhodium nanoparticles (RhNPs) on cross-linked polyvinyl alcohol–polyethyleneimine (PVA–PEI) nanofibers has been demonstrated. Various methods were firstly employed to cross-link PVA nanofibers and the cross-linked PVA–PEI nanofibers exhibited good water stability and porous structures after immersing in water for 72 h. Because of the strong chelate effects among the amine groups, hydroxyl groups and Rh³⁺ ions, uniform RhNPs with an average diameter of about 2.5 ± 0.2 nm can evenly and densely grow throughout the PVA–PEI nanofibers via an in situ reduction. Meanwhile, the better dispersion and smaller size of the RhNPs grown on the nanofibers in comparison with the pre-synthesized RhNPs directly deposited on the nanofibers exhibit the advantages of in situ reduction for size and dispersion control. The successful fabrication of the RhNPs/(PVA–PEI) nanofibers with various densities of well-dispersed RhNPs demonstrates that the strong chelate effects and stabilization of the PVA–PEI nanofibers also play an essential role in the size and dispersion control of RhNPs. The crystal structures, chemical bonding and interactions of the prepared nanofibers were verified using XPS and FTIR spectra and XRD patterns. These novel nanomaterials were fabricated as non-enzymatic electrochemical sensors and exhibit highly electrocatalytic activity towards H₂O₂.