Rational design of three-dimensional nitrogen and phosphorus co-doped graphene nanoribbons/CNTs composite for the oxygen reduction

In the present work, we report nitrogen and phosphorus co-doped 3-D structured carbon nanotube intercalated graphene nanoribbon composite. The graphene nanoribbons are prepared via partial exfoliation of multi-walled carbon nanotubes. In the graphene nanoribbons/CNTs composite, carbon nanotubes play a role of skeleton and support the exfoliated graphene nanoribbons to form the stereo structure. After high temperature heat-treatment with ammonium dihydrogen phosphate, the unique structure reserves both the properties of carbon nanotube and graphene, exhibiting excellent catalytic performance for the ORR with excellent onset and half-wave potential, which is similar to commercial Pt/C electrocatalysts.