Fe3O4 nanoparticle-decorated 3D pinewood-derived carbon for high-efficiency electrochemical nitrate reduction to ammonia

Abstract

Electrochemical nitrate (NO₃⁻) reduction is a sustainable pathway for ambient ammonia (NH₃) synthesis while eliminating NO₃⁻ pollutants in water. However, the NO₃⁻ reduction reaction (NO₃⁻RR) involves a complicated eight-electron transfer process, which needs highly selective and efficient electrocatalysts. This work describes the synthesis of Fe₃O₄ nanoparticle-decorated 3D pinewood-derived carbon (Fe₃O₄/PC) as a high-efficiency catalyst for the electroreduction of NO₃⁻ to NH₃ at ambient reaction conditions. When tested in 0.1 M NaOH containing 0.1 M NO₃⁻, the Fe₃O₄/PC obtains a large NH₃ yield of 394.8 μmol h⁻¹ cm⁻² and high faradaic efficiency (FE) of 91.6% at −0.4 V. Significantly, Fe₃O₄/PC also delivers high stability.