Synthesis of sheet-like nanoscaled ZnO and Ag/ZnO composite nanocrystals and their electrocatalytic properties

Sheet-like ZnO Ag/ZnO composites were synthesised by calcination of each precursor prepared via a hydrothermal treatment. The samples were characterised by thermogravimetric analysis and differential thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy technologies. The results showed that ZnO and Ag/ZnO composite nanosheets were composed of nanoparticles. The electrocatalytic performances of the samples modified on a glassy carbon electrode for p-nitrophenol, K₂CrO₄ and H₂O₂ reduction in a basic solution, respectively, were investigated using a cyclic voltammetry method. The results revealed that ZnO and Ag/ZnO composites with Ag content from 1 to 5% all exhibited an enhanced catalytic activity by comparing with a bare glassy carbon electrode. Among the samples, Ag/ZnO composite with 4% Ag displayed the highest catalytic activity for p-nitrophenol, and H₂O₂, but the one with 3% Ag content showed the highest catalytic activity for K₂CrO₄ reduction.