Synthesis of Au/NiO hollow micro-spheres and their adsorption and electrocatalytic properties for p-nitrophenol

The precursors of NiO and Au/NiO hollow spheres with different Au contents were prepared via a solvothermal method, and the final samples were obtained by calcining each precursor at 350 °C for 3 h. The as-synthesized samples were characterized by XRD, XPS, TEM, FE-SEM and BET, respectively. The absorption performances of NiO and Au/NiO hollow spheres for p-nitrophenol were studied. The results indicate that Au/NiO hollow spheres display higher adsorption property than pure NiO, furthermore, Au/NiO sample with 3 % Au shows the highest adsorption performance. The adsorption reagent concentration on the adsorption performance was investigated by using Au/NiO with 3 % Au. The electrocatalytic properties of the final samples modified on a glassy carbon electrode for p-nitrophenol reduction in a basic solution were investigated. The results revealed that the Au/NiO hollow spheres displayed enhanced electrocatalytic activity for p-nitrophenol reduction than NiO, and the electrocatalytic activity of the Au/NiO hollow spheres increases with increasing Au content.