A Facile Synthetic Approach for Zn₂TiO₄@NiCo₂O₄ Core‐Shell Nanoparticles Using Layered Double Hydroxide Precursors and Studies on Their Peroxidase‐Like Activity

Abstract

In the present work, a facile synthetic approach has been developed for Zn2TiO4@NiCo2O4 core‐shell nanoparticles (NPs) using layered double hydroxide (LDH) as precursors. The Zn2TiO4 microspheres (ZTS) constitute the core and the shell consists of NiCo2O4 nanoparticles. X‐ray diffraction (XRD) results confirm presence of both Zn2TiO4 and NiCo2O4 phases in Zn2TiO4@NiCo2O4 core‐shell nanoparticles. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses indicate formation of hierarchical porous shell structure of NiCo2O4 with varying thickness (132±20 nm to 171±35 nm) on the Zn2TiO4 spheres. Optical studies indicate bandgap of ~2.2 eV corresponding to NiCo2O4 nanoparticles in the Zn2TiO4@NiCo2O4 core‐shell nanoparticles. The Zn2TiO4@NiCo2O4 core‐shell nanoparticles possess high surface area (124 m2/g to 160 m2/g) as measured from Brunauer‐Emmett‐Teller (BET) analysis. Magnetic studies of Zn2TiO4@NiCo2O4 core‐shell nanoparticles indicate soft ferromagnetic and hard ferromagnetic behavior at 300 K and 5 K, respectively. The Zn2TiO4@NiCo2O4 core‐shell nanoparticles act as nanozyme and they exhibit better peroxidase‐like activity as compared to pure NiCo2O4 NPs and natural horseradish peroxidase (HRP).