Rh particles in N-doped porous carbon materials derived from ZIF-8 as an efficient bifunctional electrocatalyst for the ORR and HER.

ABSTRACT

Durable and efficient electrocatalysts toward the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) are crucial to the development of sustainable energy conversion. In this article, we report a highly active bifunctional electrocatalyst derived from ZIF-8 through simple heat-treatment activation. The resultant catalyst is enriched with Rh nanoparticles in the carbon matrix, showing excellent ORR performance with a half-wave potential (E 1/2) of 0.803 V in alkaline electrolytes; it is simultaneously active for catalyzing the HER with an overpotential of 89 mV to reach a current density of 10 mA cm2 in acidic electrolytes. The prepared RhNC-900 catalyst (1.47 wt% Rh) is comparable to the commercial Pt/C catalyst (20 wt% Pt) in terms of the ORR in alkaline media and might inspire new ideas for the development of fuel cells and water splitting.