ZnFe2O4 nanosheet array: a highly efficient electrocatalyst for ambient ammonia production via nitrite reduction

Abstract

Electrocatalytic reduction of nitrite (NO₂⁻) offers an eco-friendly and sustainable strategy for synthesizing valuable ammonia (NH₃) while simultaneously removing NO₂⁻. Nevertheless, the complexity of the six-electron transfer reaction involved can hamper NH₃ production and faradaic efficiency (FE), necessitating the quest for high-performance electrocatalysts. In this study, we introduce ZnFe₂O₄ nanosheet arrays on nickel foam (ZnFe₂O₄/NF) as an efficient electrocatalyst for the reduction of NO₂⁻ to NH₃. ZnFe₂O₄/NF demonstrates an impressive NH₃ yield of 588.58 μmol h⁻¹ cm⁻² and a remarkable FE of 95.7% at −0.6 V in 0.1 M NaOH containing 0.1 M NO₂⁻. Furthermore, it exhibits robust stability and durability throughout extended electrolysis and continuous cycling tests.