A process for the nitrogen doping of a material includes a set of carbon atoms in the sp2 hybridization state. The process further includes the material not being oxidized beforehand, then placing the material in contact with dinitrogen. Irradiating the material and the dinitrogen placed in contact with a beam of electrons or of light ions whose energy is greater than or equal to 0.1 MeV, to obtain a material wherein some of the carbon atoms in the sp2 hybridization state is nitrogen-doped.