Biotemplate derived three dimensional nitrogen doped graphene@MnO as bifunctional material for supercapacitor and oxygen reduction reaction catalyst.

Natural diatomite with abundant pores was used as a biotemplate for the massive production of three-dimensional (3D) porous graphene by chemical vapor deposition method. Subsequent template removal and nitrogen doping treatment yield nitrogen doped 3D graphene with preserved shape and complex internal features of the diatomite. After further deposition with MnO nanosheets, the N-doped 3D graphene@MnO (N-G@MnO) hybrid exhibited excellent supercapacitor and good oxygen reduction reaction (ORR) performance.