Figure 6

HER activities of different electrocatalysts.

(a) Polarization curves of N-MPG electrode, along with pure MPG, nitrogen-doped pristine graphene (N-G) and pristine graphene (G) for comparison; (b) Stability test of N-MPG through potential cycling. The scan rate is 5 mV s⁻¹ in 0.5 M H₂SO₄.