A novel MnO2/rGO composite prepared by electrodeposition as a non-noble metal electrocatalyst for ORR

A MnO2/rGO composite with a novel yarn-rod shape was fabricated by a simple, economic and environmentally friendly electrodeposition method. The as-prepared MnO2/rGO composite was systematically characterized via X-ray Diffraction, X-ray Photoelectron Spectroscopy, Raman Spectra, Scanning Electron Microscope, Transmission Electron Microscope, and Specific Surface Area measurement. The experimental results indicate that the MnO2 nanoparticles with rod-like morphology scatter over the yarn-shaped rGO sheet through the electrodeposition procedure. The current density of O-2 reduction on the MnO2/rGO composite modified electrode is higher than those on MnO2 and rGO. The initial oxygen-reduction peak potential and half-wave potential of the MnO2/rGO composite are more positive than those of MnO2 and rGO. The MnO2/rGO composite, as a non-noble metal oxide catalyst, not only exhibits superior electrocatalytic activity for oxygen-reduction reaction (ORR) in an alkaline medium compared with MnO2 and rGO but also shows better ORR stability, higher electron transfer numbers, and stronger methanol-tolerant ability than the commercial Pt/C catalyst. These considerable results enable the development of a cheap and efficient non-noble metal electrocatalyst for ORR in fuel cells.Graphic abstractThe MnO2/RGO composite prepared by the facile electrodeposition method shows the comparable electrocatalytic ORR performance with Pt/C [GRAPHICS] .