fig4
Figure 4. (A) Polarization curves of NiOx@DG, NiOx@DG-9, NiOx-DG, NiOx NS-350 and NiOx NS-550 on RRDE at 1,600 rpm in O2-saturated 0.1 M KOH; (B) The calculated H2O2 selectivity and Transfer electron n of catalysts; (C and D) Tafel slope of NiOx@DG, NiOx@DG-9, NiOx-DG, NiOx NS-350 and NiOx NS-550; (E and F) Stability test of NiOx@DG catalyst after 5,000 cycles. DG: Defective graphene; RRDE: rotating ring disc electrode; n: number; RHE: reversible hydrogen electrode.
