Rationally designed hierarchical nickel nanoparticles-based magnetic yolk-like nanospindles for enhanced catalysis and protein adsorption

Abstract

Utilization of hierarchical nickel silicate along with mussel chemistry for the construction of metallic Ni nanoparticles (NPs) inside silica framework offers great advantages in the rational design of advanced catalysts and protein adsorbents. Herein, we demonstrate that by coating a thin layer of polydopamine (PDA) on the surface of Fe₂O₃@nickel silicate (Fe₂O₃@NS) followed by subsequent thermal treatment in a nitrogen atmosphere, high density of metallic Ni NPs immobilized magnetic yolk-like nanospindles can be synthesized. Notably, the density and diameter of the Ni NPs as well as components of the Fe₂O₃ core were effectively tailored by changing the carbonization temperature. Moreover, this strategy could be extended to other cores with different morphologies and components such as Fe₃O₄ spheres and MnO₂ nanowires (NWs), thus verifying the versatility of this process. Owing to the unique structure and high density of the Ni NPs of the FeO_x@SiO₂@C–Ni nanocomposites, the resultant products exhibited excellent performance in catalysing the reduction of 4-NP and adsorption of histidine-rich proteins.