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

Electrochemical reduction of nitrite (NO2-) can satisfy the necessity for NO2- contaminant removal and deliver a sustainable pathway for ammonia (NH3) gener-ation. Its practical application yet requires highly efficient electrocatalysts to boost NH3 yield and Faradaic efficiency (FE). In this study, CoP nanoparticle-decorated TiO2 nanoribbon array on Ti plate (CoP@TiO2/TP) is verified as a high-efficiency electrocatalyst for the selective reduction of NO2- to NH3. When measured in 0.1 M NaOH with NO2-, the freestanding CoP@TiO2/TP electrode delivers a large NH3 yield of 849.57 mmol h(-1) cm(-2) and a high FE of 97.01% with good stability. Remarkably, the subsequently fabricated Zn-NO2- battery achieves a high power density of 1.24 mW cm(-2) while delivering a NH3 yield of 714.40 mg h(-1) cm(-2).

Automated summary

This study verifies that CoP nanoparticle-decorated TiO2 nanoribbon array on Ti plate (CoP@TiO2/TP) is a highly efficient electrocatalyst for the selective reduction of NO2- to NH3. The freestanding CoP@TiO2/TP electrode delivers a large NH3 yield of 849.57 mmol h(-1) cm(-2) and a high Faradaic efficiency (FE) of 97.01% with good stability in 0.1 M NaOH solution with NO2-. Remarkably, the subsequently fabricated Zn-NO2- battery achieves a high power density of 1.24 mW cm(-2) while delivering a NH3 yield of 714.40 mg h(-1) cm(-2).