Mechanistic insight into collectively exhaustive CoPi-NPC nanosheets for oxygen reduction reaction and Zn-air battery

Abstract

Here, we report a collectively exhaustive CoPi-NPC (cobalt phosphate moieties incorporated into the N, P- doped carbon) nanosheets for oxygen reduction reaction (ORR) and rechargeable zinc-air battery (ZAB) applications. The unprecedented CoPi-NPC nanosheets were synthesized from the cobalt-diethyl dithiocarbamate coordination complex by using room-temperature crystallization and carbonization processes. The fabricated nanosheets catalyze the critical ORR via a four-electron transfer through an associative reaction pathway in which the Osingle bondO bond cleavage can be recognized as the rate-determining step, offering high positive onset (∼0.925 V vs. RHE) and the half-wave potentials (E1/2 = ∼0.796 V vs. RHE). The assembled ZAB based on porous CoPi-NPC-900 air cathode delivered the maximum power density of ∼186 mW cm−2, and large specific capacity of ∼729 mAh g−1. Hence, this study opens up a new avenue to exploit various efficient non-precious electrocatalysts through different transition metal-diethyl dithiocarbamate coordination complexes.