Synthesis and electrocatalytic performance for p-nitrophenol reduction of rod-like Co3O4 and Ag/Co3O4 composites

Rod-like precursors of Co3O4 and Ag/Co3O4 composites with different Ag contents were synthesized via a co-precipitation method. Co3O4 and Ag/Co3O4 composite samples were fabricated by calcining each precursor at 400 °C for 3 h. The as-prepared samples were characterized by thermogravimetric analysis and differential thermal gravimetric analysis (TGA/DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), respectively. Co3O4 and Ag/Co3O4 composites were used as electrocatalyst modified on a glassy carbon electrode for p-nitrophenol reduction in basic solution. The results showed that p-nitrophenol could be reduced effectively on the modified electrode. By comparison with a bare glassy carbon electrode, peak current increased markedly with Co3O4 and Ag/Co3O4 samples, and peak potential decreased obviously with Ag/Co3O4 samples. Ag/Co3O4 composites with 4% Ag exhibited the highest electrocatalytic activity for p-nitrophenol reduction.