Enabling Effective Electrocatalytic N-2 Conversion to NH3 by the TiO2 Nanosheets Array under Ambient Conditions

NH3 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-2 to NH3, while it needs efficient electrocatalysts for the N-2 reduction reaction (NRR) to meet the challenge associated with N-2 activation. In this Letter, we report on our recent experimental finding that the TiO2 nanosheets array on the Ti plate (TiO2/Ti) is effective for electrochemical N-2 conversion to NH3 at ambient conditions. When tested in 0.1 M Na2SO4, such TiO2/Ti attains a high NH3 yield of 9.16 x 10(-11) mol s(-1).cm(-2) 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 NH3 formation with high electrochemical stability. The superior NRR activity is due to the enhanced adsorption and activation generated during electrochemical tests. of N-2 by oxygen vacancies in situ generated during electrochemical tests.