A 3D FeOOH nanotube array: an efficient catalyst for ammonia electrosynthesis by nitrite reduction

Nitrite (NO2-) is a detrimental pollutant widely existing in groundwater sources, threatening public health. Electrocatalytic NO2- reduction settles the demand for removal of NO2- and is also promising for generating ammonia (NH3) at room temperature. A nanotube array directly grown on a current collector not only has a large surface area, but also exhibits improved structural stability and accelerated electron transport. Herein, a self-standing FeOOH nanotube array on carbon cloth (FeOOH NTA/CC) is proposed as a highly active electrocatalyst for NO2--to-NH3 conversion. As a 3D catalyst, the FeOOH NTA/CC is able to attain a surprising faradaic efficiency of 94.7% and a large NH3 yield of 11937 mu g h(-1) cm(-2) in 0.1 M PBS (pH = 7.0) with 0.1 M NO2-. Furthermore, this catalyst also displays excellent durability in cyclic and long-term electrolysis tests.

Automated summary

In this study, a self-standing FeOOH nanotube array on carbon cloth was proposed as a highly active electrocatalyst for the conversion of nitrite to ammonia. The results showed that the catalyst exhibited high conversion efficiency and ammonia yield, and also demonstrated excellent durability in cyclic and long-term tests.