Oxygen reduction reaction activity of LaMn1-xCoxO3-graphene nanocomposite for zinc-air battery

• DOI: 10.1016/j.electacta.2015.02.048
• Publication Date: 2015-02-07T17:39:12Z
• Authors: Jie Hu; Lina Wang; Lina Shi; Hao Huang
• Keywords: Rotating disk electrode

Abstract Cobalt doped LaMnO 3 -graphene composites are prepared by sol-gel process assisted with chelating effect of citric acid. The structure, morphology and valence state of samples are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). Results show that LaMn 1-x Co x O 3 particles are homogeneously dispersed on graphene nanosheets, and that doping Co does not change the pervoskite structure. Electrochemical properties are characterized by rotating disk electrode (RDE), rotating ring-disk electrode (RRDE), galvanostatic discharge and AC impedance spectra techniques. The sample prepared with x = 0.1 possesses excellent electrocatalytic activity for oxygen reduction reaction (ORR) and good electrochemical stability in alkaline medium. The measurements of RDE and RRDE reveal that the electron transfer number of LaMn 0.9 Co 0.1 O 3 -graphene is calculated to be 3.87. All the above results indicate that the LaMn 1-x Co x O 3 -graphene composites are promising catalysts with a high catalytic activity toward ORR.