Synergistic effects at the interface of core-shell Cu₃P@CoO heterojunctions for enhanced nitrate reduction to ammonia

Abstract

Electrocatalytic nitrate reduction (NO3RR) is promising as an environmentally friendly process to produce high value-added ammonia with simultaneous removal of nitrate, a widespread nitrogen pollutant, for water treatment; however, efficient electrocatalysts with high selectivity are required for ammonia formation. In this work, core-shell Cu3P@CoO heterojunction is proposed as a high-performance electrocatalyst for converting nitrate to ammonia at room temperature. When operated in a 0.1 M NaOH solution with 0.1 M NaNO3, Cu3P@CoO is able to obtain a large NH3 yield of 9201 μg h−1 cm−2 and a surprisingly high Faradic efficiency of 92 % with excellent stability. Density functional theory calculation demonstrates that the high NO3RR activity of a- Cu3P@CoO is attributed to the synergistic cascade effect of core-shell Cu3P and CoO at the heterojunction interface. This work provides a strategy for designing multi-site cascade catalysts centered on core-shell structures to achieve efficient NO3RR.