Enhanced NH(3) Synthesis from Air in a Plasma Tandem-Electrocatalysis System Using Plasma-Engraved N-Doped Defective MoS(2)

[Image: see text] We have developed a sustainable method to produce NH(3) directly from air using a plasma tandem-electrocatalysis system that operates via the N(2)–NO(x)–NH(3) pathway. To efficiently reduce NO(2)(–) to NH(3), we propose a novel electrocatalyst consisting of defective N-doped molybdenum sulfide nanosheets on vertical graphene arrays (N-MoS(2)/VGs). We used a plasma engraving process to form the metallic 1T phase, N doping, and S vacancies in the electrocatalyst simultaneously. Our system exhibited a remarkable NH(3) production rate of 7.3 mg h(–1) cm(–2) at −0.53 V vs RHE, which is almost 100 times higher than the state-of-the-art electrochemical nitrogen reduction reaction and more than double that of other hybrid systems. Moreover, a low energy consumption of only 2.4 MJ mol(NH(3))(–1) was achieved in this study. Density functional theory calculations revealed that S vacancies and doped N atoms play a dominant role in the selective reduction of NO(2)(–) to NH(3). This study opens up new avenues for efficient NH(3) production using cascade systems.