Ti3+ self-doped TiO2-x nanowires for efficient electrocatalytic N2 reduction to NH3.

Electrochemical N2 reduction is an environmentally friendly and sustainable approach for NH3 synthesis under mild conditions, while an efficient electrocatalyst is crucial for the N2 reduction reaction (NRR). Herein, we report Ti3+ self-doped TiO2-x nanowires on Ti mesh (Ti3+-TiO2-x/TM) as an efficient non-noble-metal NRR electrocatalyst with excellent selectivity. In 0.1 M Na2SO4, the Ti3+-TiO2-x/TM achieves a high faradaic efficiency of 14.62% with a NH3 yield of 3.51 × 10-11 mol s-1 cm-2 at -0.55 V vs. the reversible hydrogen electrode. Density functional theory calculations further reveal that introducing Ti3+ decreases the reaction energy barrier and increases the number of active sites on the TiO2 surface for the NRR.