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

Abstract Developing sustainable energy solutions is critical for addressing the dual challenges of energy demand and environmental impact. In this study, a zinc‐nitrate (Zn−NO 3 − ) battery system was designed for the simultaneous production of ammonia (NH 3 ) via the electrocatalytic NO 3 − reduction reaction (NO 3 RR) and electricity generation. Continuous wave CO 2 laser irradiation yielded precisely controlled CoFe 2 O 4 @nitrogen‐doped carbon (CoFe 2 O 4 @NC) hollow nanocubes from CoFe Prussian blue analogs (CoFe‐PBA) as the integral electrocatalyst for NO 3 RR in 1.0 M KOH, achieving a remarkable NH 4 + production rate of 10.9 mg h −1 cm −2 at −0.47 V versus Reversible Hydrogen Electrode with exceptional stability. In situ and ex situ methods revealed that the CoFe 2 O 4 @NC surface transformed into high‐valent Fe/CoOOH active species, optimizing the adsorption energy of NO 3 RR (*NO 2 and *NO species) intermediates. Furthermore, density functional theory calculations validated the possible NO 3 RR pathway on CoFe 2 O 4 @NC starting with NO 3 − conversion to *NO 2 intermediates, followed by reduction to *NO. Subsequent protonation forms the *NH and *NH 2 species, leading to NH 3 formation via final protonation. The Zn−NO 3 − battery utilizing the CoFe 2 O 4 @NC cathode exhibits dual functionality by generating electricity with a stable open‐circuit voltage of 1.38 V versus Zn/Zn 2+ and producing NH 3 . This study highlights the innovative use of CO 2 laser irradiation to transform Prussian blue analogs into cost‐effective catalysts with hierarchical structures for NO 3 RR‐to‐NH 3 conversion, positioning the Zn−NO 3 − battery as a promising technology for industrial applications.