High-efficiency electrocatalytic nitrite reduction toward ammonia synthesis on CoP@TiO2 nanoribbon array

Electrochemical reduction of nitrite (NO 2 − ) can satisfy the necessity for NO 2 − contaminant removal and deliver a sustainable pathway for ammonia (NH 3 ) generation. Its practical application yet requires highly efficient electrocatalysts to boost NH 3 yield and Faradaic efficiency (FE). In this study, CoP nanoparticle-decorated TiO 2 nanoribbon array on Ti plate (CoP@TiO 2 /TP) is verified as a high-efficiency electrocatalyst for the selective reduction of NO 2 − to NH 3 . When measured in 0.1 M NaOH with NO 2 − , the freestanding CoP@TiO 2 /TP electrode delivers a large NH 3 yield of 849.57 μmol h −1 cm −2 and a high FE of 97.01% with good stability. Remarkably, the subsequently fabricated Zn–NO 2 − battery achieves a high power density of 1.24 mW cm −2 while delivering a NH 3 yield of 714.40 μg h −1 cm −2 .