Solar Ammonia Synthesis: Near-Complete Conversion of Intermediated Nitrogen Energy Carrier via the N2–NO–NH3 Route

N2 fixation into NH3 under ambient conditions remains greatly challenging, where a relay scheme by plasma-enabled N2 oxidation (pN2OR) and the NO reduction reaction (NORR) can be a practical route. However, the efficient conversion of NO, as the intermediate nitrogen energy carrier, has not been accomplished due to the limited mass transfer of NO in the reaction solution. Here, a tandem pN2OR and photocatalytic NORR route (N2-NO-NH3) is developed to achieve sustainable NH3 synthesis with near-complete NO conversion. The highly concentrated NO (∼1%), produced via pN2OR, is introduced to an absorption-photocatalysis scheme, where the efficiencies for synchronous NO dissolution and photoreduction are significantly promoted. This system delivers a near 100% NO conversion ratio and superior NH3 selectivity (98.33% ± 0.75%) and stability (240 h) in a single-pass continuous flow. This research has successfully developed a highly profitable production route, yielding a substantial profit of $3000 per ton for NH4COOH as the final product.