Nitrogen-doped porous carbon: highly efficient trifunctional electrocatalyst for oxygen reversible catalysis and nitrogen reduction reaction

Abstract

Simple yet efficient design of an outstanding multifunctional electrocatalyst is crucial for advanced energy conversion and storage devices. Herein, we report the synthesis of an N-enriched hierarchically porous carbon electrocatalyst, which demonstrated excellent overall oxygen electrode activity (ΔE = E_OER,10 − E_ORR,1/2 of 0.770 V) and impressive durability in 0.1 M KOH. The activity of our material integrates a high BET surface area (1547.13 m² g⁻¹), accessible N dopant and suitable porous architectures. The material is formed by mixing cicada sloughs with ZnCl₂, as the inorganic pore-fabricating agent, with ball milling followed by annealing treatment. Unexpectedly, the nitrogen reduction reaction (NRR) with excellent production yield (NH₃: 15.7 μg h⁻¹ mg⁻¹ cat., faradaic efficiency: 1.45%) and selectivity is achieved at −0.2 V vs. RHE under ambient conditions. The present trifunctional catalytic activities are markedly better than leading results reported in recent literature. These results highlight the significance of deliberate structural engineering in the preparation of multifunctional electrocatalysts for versatile electrochemical reactions.