A general synthesis and electrocatalytic activity of low-dimensional MO and M–Co (MCu, Ni, Zn and Cd) composite oxides

An assisting template with cyclohexylamine was used to synthesize low-dimensional Co3O4, MO, M–Co (MCu, Ni, Zn and Cd) composite oxides with M/Co atomic ratio of 1:2. The as-synthesized samples were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results indicated that Co3O4 and CdO possessed sheet-like morphologies, NiO demonstrated belt-like morphology, ZnO represented rod-like shape. The morphologies of the composite M–Co oxides (MCu and Cd) represented rod-like shape, Ni–Co and Zn–Co oxides exhibited belt-like and sheet-like morphologies. According to phase analysis with XRD technology, M–Co (MCu, Ni and Zn) possessed MCo2O4 spinel structure but Cd–Co oxides revealed a hybrid structure. The electrocatalytic activity for p-nitrophenol reduction with a glassy carbon electrode modified with the as-prepared metal oxides or M–Co composite oxides was investigated in a basic solution, and the results indicated that NiO and Co3O4 showed a certain but CdO and ZnO a little electrocatalytic activity for p-nitrophenol reduction, while M–Co composite oxides all revealed high electrocatalytic activity for the reduction of p-nitrophenol.