In Situ Derived Co 2 B Nanosheet Array: A High-Efficiency Electrocatalyst for Ambient Ammonia Synthesis via Nitrate Reduction.

Ambient ammonia synthesis via electrochemical nitrate (NO) reduction is regarded as a green alternative to the Haber-Bosch process. Herein, we report the in situ derivation of an amorphous CoB layer on a CoO nanosheet array on a Ti mesh (CoB@CoO/TM) for efficient NH production via selective electroreduction of NO under ambient conditions. In 0.1 M PBS and 0.1 M NaNO, CoB@CoO/TM exhibits a maximum Faradaic efficiency of 97.0% at -0.70 V and a remarkable NH yield of 8.57 mg/h/cm at -1.0 V, with durability for stable NO-to-NH conversion over eight recycling tests and 12 h of electrolysis. Additionally, it can be applied as an efficient cathode material for Zn-NO batteries to produce NH while generating electricity. The catalytic mechanisms on CoB@CoO are further revealed by theoretical calculations.