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

Considering that few studies explored CoS 2 as electrocatalyst for hydrogen peroxide (H 2 O 2 ) reduction, in this paper, a hybrid composite of porous CoS 2 nanocages decorated with Au nanopar(1)ticles (Au/CoS 2 ) was synthesized by sulfurizing ZIF-67 and reducing Au 3+ , where ZIF-67 made CoS 2 form a porous nanocage structure and Au-S bonds enabled CoS 2 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 CoS 2 nanocage and Au nanoparticles made the sensor based on Au/CoS 2 exhibit remarkable performance for H 2 O 2 detection, including a linear range of 0.022 mM–3.5 mM, a sensitivity of 50 μ A mM −1 cm −2 and a low detection limit of 0.02 mM, confirming Au/CoS 2 as a promising material for electrochemical sensing of H 2 O 2 .