Enabling Effective Electrocatalytic N Conversion to NH by the TiO Nanosheets Array under Ambient Conditions.

NH serves as an attractive hydrogen storage medium and a renewable energy sector for a sustainable future. Electrochemical reduction is a feasible ambient reaction to convert N to NH, while it needs efficient electrocatalysts for the N reduction reaction (NRR) to meet the challenge associated with N activation. In this Letter, we report on our recent experimental finding that the TiO nanosheets array on the Ti plate (TiO/Ti) is effective for electrochemical N conversion to NH at ambient conditions. When tested in 0.1 M NaSO, such TiO/Ti attains a high NH yield of 9.16 × 10 mol s·cm with corresponding Faradaic efficiency of 2.50% at -0.7 V vs reversible hydrogen electrode, outperforming most reported aqueous-based NRR electrocatalysts. It also shows excellent selectivity for NH formation with high electrochemical stability. The superior NRR activity is due to the enhanced adsorption and activation of N by oxygen vacancies in situ generated during electrochemical tests.