3.4% Solar‐to‐Ammonia Efficiency from Nitrate Using Fe Single Atomic Catalyst Supported on MoS ₂ Nanosheets

Electrochemical synthesis of NH3 is a carbon-free alternative to the traditional Haber–Bosch process. Obtaining from environmental pollutants, such as nitrates or nitrites, more practical route than nitrogen reduction reaction (NRR) due difficult cleavage inert triple bond gas. Here, novel heterogeneous catalyst reported based on iron (Fe) single-atoms supported 2D MoS2 (Fe-MoS2) for nitrate (NO3RR). Fe-MoS2 exhibits remarkable performance with maximum Faradaic efficiency 98% NO3RR at an onset potential −0.48 V versus reversible hydrogen electrode (RHE) confirmed by isotopic nuclear magnetic resonance (NMR) analyses. Density functional theory (DFT) calculations reveal that enhanced selectivity production single Fe atoms attributed reduced energy barrier 0.38 eV associated de-oxidation *NO *N. The catalysts are coupled InGaP/GaAs/Ge triple-junction solar cell demonstrate solar-to-ammonia (STA) conversion 3.4% and yield rate 510 µg h−1 cm−2. results open new avenues design single-atom (SAC) realization solar-driven ammonia production.