Nitrogen-doped carbon-based electrocatalysts synthesised by ball-milling

Herein, for the first time, ball-milling of carbon materials (e.g. graphite, graphene oxide or graphene) in the presence of dicyandiamide (DCDA) followed by heat treatment at 800 degrees C was employed to synthesise N-doped carbons for the oxygen reduction reaction (ORR) in alkaline medium. The obtained results highlight that: i) the N-doped nanocarbon catalysts synthesis process employed herein is easy and could be used without hazardous solvents; ii) X-ray photoelectron spectroscopy indicated successful N-doping, iii) N-doped graphite and graphene are Mn-free as confirmed by the ICP-MS analysis, iv) the ORR electrocatalytic activity depends on the carbon source used for the catalyst preparation and v) all the N-doped nanocarbons revealed better ORR performance than the undoped materials.