Hydrated FePO4 nanoparticles supported on P-doped RGO show enhanced ORR activity compared to their dehydrated form in an alkaline medium

Abstract

One-step hydrothermal growth of FePO4 nanoparticles (15-25 nm) uniformly decorated on the P-doped reduced graphene oxide (PRGO) was studied for oxygen reduction reaction (ORR) activity. The role of lattice water in the enhancement of catalytic activity in the hydrated FePO4·2H2O with respect to its dehydrated form in the alkaline medium was contested. The hydrodynamic LSV at 1600 rpm in alkaline medium (0.1 M KOH electrolyte) indicates an increase in the cathodic current density of the PRGO supported FePO4·2H2O catalyst, which reaches as high as 5.8 mA cm-2, close to the best known commercially available Pt/C catalyst. The stability in terms of retention of activity after 22000 s with the hydrated form was found to be 90.7% which is 26.7% higher than that of the dehydrated form.