| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 184164 | Electrochimica Acta | 2015 | 9 Pages |
•LaMn1-xCoxO3–graphene composites were synthesized for the first time.•Oxygen reduction reaction activity of composites in alkaline medium was evaluated.•The electrocatalytic activity of composites was enhanced than pure LaMnO3 oxides.
Cobalt doped LaMnO3-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 LaMn1-xCoxO3 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 LaMn0.9Co0.1O3-graphene is calculated to be 3.87. All the above results indicate that the LaMn1-xCoxO3-graphene composites are promising catalysts with a high catalytic activity toward ORR.
Graphical abstractCobalt doped porous LaMnO3-graphene composites possess excellent electrocatalytic activity for oxygen reduction reaction and good electrochemical stability in alkaline medium.Figure optionsDownload full-size imageDownload as PowerPoint slide
