S and N codoped three-dimensional graphene-MnS hybrids with high electrocatalytic activity for oxygen reduction reaction

Sulfur and nitrogen codoped three-dimensional graphene-MnS (MnS/S,N-3DG) hybrids are facilely synthesized via a hydrothermal method followed by freeze-drying and pyrolysis treatment. The obtained MnS/S,N-3DG as an electrocatalyst for oxygen reduction reaction (ORR) shows excellent electrocatalytic performance. The codoped S and N as well as the introduced MnS significantly promote the electrocatalytic activity of graphene and efficiently catalyze the ORR process through a mixture of two-electron transfer pathway and four-electron transfer pathway (electron transfer number equals to 3.8 or 3.9), which is even better than the commercial Pt (5%)/C catalyst. Moreover, the developed MnS/S,N-3DG electrocatalyst possesses excellent long-term stability and methanol tolerance, and could be a promising cathode electrocatalyst in future energy conversion and storage systems.