Homogeneous Decoration of Au Nanoparticles on ZIF-Derived Porous CoS2 Nanocages for Nonenzymatic Hydrogen Peroxide Sensing

Abstract

Considering that few studies explored CoS2 as electrocatalyst for hydrogen peroxide (H2O2) reduction, in this paper, a hybrid composite of porous CoS2 nanocages decorated with Au nanopar(1)ticles (Au/CoS2) was synthesized by sulfurizing ZIF-67 and reducing Au3+, where ZIF-67 made CoS2 form a porous nanocage structure and Au-S bonds enabled CoS2 as a promising support for facilitating homogeneous decoration of Au nanoparticles. TEM images supported the porous nanocage structure with homogeneous distribution of Au nanoparticles. Such porous structure is beneficial for promoting target substance diffusion, and the decoration of Au nanoparticles not only increases active sites for reaction but also facilitates electron transport. Therefore, the synergistic interaction between CoS2 nanocage and Au nanoparticles made the sensor based on Au/CoS2 exhibit remarkable performance for H2O2 detection, including a linear range of 0.022 mM–3.5 mM, a sensitivity of 50 μA mM−1 cm−2 and a low detection limit of 0.02 mM, confirming Au/CoS2 as a promising material for electrochemical sensing of H2O2.