Antiperovskite Nitrides CuNCo_3-V: Highly Efficient and Durable Electrocatalysts for the Oxygen-Evolution Reaction

Perovskite oxides have attracted much attention for enabling the oxygen-evolution reaction (OER) over the past decades. Nevertheless, their poor conductivity is still a barrier hindering their use. Herein, we report a catalyst prototype of Co-based antiperovskite nitrides CuNCo_3-V (0 ≤ x ≤ 1) to be a highly effective OER electrocatalyst. The synthesized CuNCo_3-V exhibits greatly enhanced activity and stability toward the OER in alkaline medium. The CuNCo_2.4V_0.6 shows a mere 235 mV of overpotential to reach 10 mA cm^-2, which is comparable to that of Ir/C (232 mV). More importantly, the CuNCo_2.4V_0.6 is more durable than the conventional Ir/C catalyst. The CuNCo_2.4V_0.6 catalyst enabled a Zn-air battery to exhibit a cycle life of 143 h with a much higher cell efficiency. The V-substituted CuNCo_2.4V_0.6 provides a higher content of the desirable Co³⁺ species in the post-OER catalyst, which ensures a high activity over a long-term operation. With these enhanced effects enabled by the compositional flexibility of CuNCo_3-V antiperovskite nitride, a feasible strategy for optimizing an electrocatalyst with tunable properties is provided.