Photothermally enhanced ammonia synthesis and Zn-nitrite battery performance enabled by bimetallic Cu-Ni synergy

<h2>Summary</h2> The electroreduction of nitrite (NO₂⁻) to ammonia (NH₃) offers dual benefits for resource valorization and wastewater remediation but suffers from limitations in active hydrogen (∗H) management and external energy utilization. Here, we report a photothermal electrocatalyst of Cu-Ni-FeOOH for efficient NO₂⁻-to-NH₃ conversion. Experimental and theoretical investigations reveal that Ni centers promote water dissociation, supplying ∗H to adjacent Cu sites for NO₂⁻ hydrogenation. The catalyst achieves a high Faradaic efficiency of 98.6% with an NH₃ yield of 8.86 mg h⁻¹ cm⁻² at −0.1 V vs. reversible hydrogen electrode (RHE). When exposed to near-infrared light irradiation, the <i>in situ</i>-generated thermal energy further enhances the electrocatalytic activity for NO₂⁻ reduction and improves the performance of a Zn-nitrite battery. This work provides a strategic direction for sustainable NH₃ synthesis through the design of advanced electrocatalytic systems synergistically coupled with external photothermal fields.