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

The electroreduction of nitrite (NO 2 − ) to ammonia (NH 3 ) 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 NO 2 − -to-NH 3 conversion. Experimental and theoretical investigations reveal that Ni centers promote water dissociation, supplying ∗H to adjacent Cu sites for NO 2 − hydrogenation. The catalyst achieves a high Faradaic efficiency of 98.6% with an NH 3 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 in situ -generated thermal energy further enhances the electrocatalytic activity for NO 2 − reduction and improves the performance of a Zn-nitrite battery. This work provides a strategic direction for sustainable NH 3 synthesis through the design of advanced electrocatalytic systems synergistically coupled with external photothermal fields.