Abstract
NiCo2O4 nanowire array on carbon cloth (NiCo2O4/CC) is proposed as a highly active electrocatalyst for ambient nitrate (NO3-) reduction to ammonia (NH3). In 0.1 m NaOH solution with 0.1 m NaNO3, such NiCo2O4/CC achieves a high Faradic efficiency of 99.0% and a large NH3 yield up to 973.2 mu mol h(-1) cm(-2). The superior catalytic activity of NiCo2O4 comes from its half-metal feature and optimized adsorption energy due to the existence of Ni in the crystal structure. A Zn-NO3- battery with NiCo2O4/CC cathode also shows a record-high battery performance.