Mitigating Intraphase Catalytic‐Domain Transfer via CO2 Laser for Enhanced Nitrate‐to‐Ammonia Electroconversion and Zn‐Nitrate Battery Behavior

Developing sustainable energy solutions is critical for addressing the dual challenges of energy demand and environmental impact. In this study, a zinc‐nitrate (Zn‐NO3−) battery system was designed for the simultaneous production of ammonia (NH3) via the electrocatalytic NO3− reduction reaction (NO3RR) and electricity generation. Continuous wave CO2 laser irradiation yielded precisely controlled CoFe2O4@nitrogen‐doped carbon (CoFe2O4@NC) hollow nanocubes from CoFe Prussian blue analogs (CoFe‐PBA) as the integral electrocatalyst for NO3RR in 1.0‐M KOH, achieving a remarkable NH3 production rate of 10.9 mgh−1cm−2 at −0.47 V versus RHE with exceptional stability. In‐situ and ex‐situ methods revealed that the CoFe2O4@NC surface transformed into high‐valent Fe/CoOOH active‐species, optimizing the adsorption energy of NO3RR (*NO2 and *NO species) intermediates. Furthermore, DFT calculations validated the possible NO3RR pathway on CoFe2O4@NC starting with NO3− conversion to *NO2 intermediates, followed by reduction to *NO. Subsequent protonation forms the *NH and *NH2 species, leading to NH3 formation via final protonation. The Zn‐NO3− battery utilizing the CoFe2O4@NC cathode exhibits dual functionality by generating electricity with a stable open‐circuit voltage of 1.38‐V versus Zn/Zn2+ and producing NH3. This study inspires the simple design of low‐cost catalysts for NO3RR‐to‐NH3 conversion and positions the Zn‐NO3− battery as a promising technology for industrial applications.