Antiperovskite Nitrides CuNCo<sub>3-<i>x</i></sub>V<sub><i>x</i></sub>: Highly Efficient and Durable Electrocatalysts for the Oxygen-Evolution Reaction.

Zhang, Jiaxi; Zhao, Xiao; Du, Li; Li, Yutao; Zhang, Longhai; Liao, Shijun; Goodenough, John B; Cui, Zhiming · Nano Lett · 2019

basic_science · Level V

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Abstract

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<sub>3-<i>x</i></sub>V<sub><i>x</i></sub> (0 ≤ <i>x</i> ≤ 1) to be a highly effective OER electrocatalyst. The synthesized CuNCo<sub>3-<i>x</i></sub>V<sub><i>x</i></sub> exhibits greatly enhanced activity and stability toward the OER in alkaline medium. The CuNCo<sub>2.4</sub>V<sub>0.6</sub> shows a mere 235 mV of overpotential to reach 10 mA cm<sup>-2</sup>, which is comparable to that of Ir/C (232 mV). More importantly, the CuNCo<sub>2.4</sub>V<sub>0.6</sub> is more durable than the conventional Ir/C catalyst. The CuNCo<sub>2.4</sub>V<sub>0.6</sub> catalyst enabled a Zn-air battery to exhibit a cycle life of 143 h with a much higher cell efficiency. The V-substituted CuNCo<sub>2.4</sub>V<sub>0.6</sub> provides a higher content of the desirable Co<sup>3+</sup> 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<sub>3-<i>x</i></sub>V<sub><i>x</i></sub> antiperovskite nitride, a feasible strategy for optimizing an electrocatalyst with tunable properties is provided.