An efficient and durable trifunctional electrocatalyst for zinc–air batteries driven overall water splitting

Constructing more active and durable trifunctional electrocatalysts is key for boosting overall water splitting and metal–air battery efficiency. Herein, we developed a trifunctional electrocatalyst of ultrafine Pt nanoparticles anchored on CoS2-N-doped reduced graphene oxide ([email protected]2-NrGO). Owing to its more Pt active sites with rapid ion/electron transport ability, the [email protected]2-NrGO shows excellent trifunctional activities towards HER (ƞ10 = 39 mV), OER (ƞ10 = 235 mV) ORR (E1/2 = 0.85 V vs. RHE) and water splitting device of [email protected]2-NrGO||[email protected]2-NrGO achieved cell voltage of 1.48 V at 10 mA cm−2, which is better than Pt-C||RuO2. Finally, we employed [email protected]2-NrGO as air cathode for zinc–air battery to display a power density of 114 mW cm-2 and durability of 55 h, outperforming than Pt-C + RuO2 based zinc–air batteries. For practical aspects, [email protected]2-NrGO based zinc–air batteries were connected to overall water splitting device to produce H2 and O2 gases for hydrogen fuel cell.