Figure 4
STM images of N–doped graphene dominant with graphitic N and pyrrolic N.
(a) Large–scale STM topographic image of graphitic N dominated graphene on Cu foil showing the presence of pointlike N dopants (Vbias = −0.015 V, Iset = 0.3 nA). Scale bar = 5 nm. (b) High–resolution STM image of graphitic N dopant (Vbias = −0.015 V, Iset = 0.3 nA). Scale bar = 1 nm. (c) Scheme of graphitic N. (d) Large–scale STM topographic image of pyrrolic N dominated graphene on Cu foil (Vbias = −0.02 V, Iset = 0.3 nA). Scale bar = 2 nm. (e) High–resolution STM image of pyrrolic N dopant (Vbias = −0.02 V, Iset = 0.3 nA). Scale bar = 1 nm. (f) Scheme of pyrrolic N. The red and black balls in (c,f) represent nitrogen and carbon atoms, respectively.
