Iron-Doped MoO Nanosheets for Boosting Nitrogen Fixation to Ammonia at Ambient Conditions.

Nitrogen can be electrochemically reduced to produce ammonia, which supplies an energy-saving and environmental-benign route at room temperature, but high-efficiency catalysts are sought to reduce the reaction barrier. Here, iron-doped α-MoO nanosheets are thus designed and proposed as potential catalysts for fixing N to NH. The α-MoO band structure is intentionally modulated by the iron doping, which narrows the band gap of α-MoO and turns the semiconductor into a metal-like catalyst. Oxygen vacancies, generated by substituting Mo for Fe anions, are beneficial for nitrogen adsorption at the active sites. In 0.1 M NaSO, the Fe-doped MoO catalyst reached a high faradaic efficiency of 13.3% and an excellent NH yield rate of 28.52 μg h mg at -0.7 V versus reversible hydrogen electrode, superior to most of the other metal-based catalysts. Theoretical calculations confirmed that the N reduction reaction at the Fe-MoO surface followed the distal reaction path.