Electrochemical Reduction of N2 into NH3 under Ambient Conditions Using Ag-doped TiO2 Nanofibers

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The efficient electrochemical synthesis of ammonia (NH 3 ) is a topic of great concern in theoretical research and in various industries. However, given the limitations of high-performance catalysts, achieving high NH 3 yields from the electrocatalytic N 2 reduction reaction (ENRR) remains challenging. In this work, we report that a Ag-doped titanium dioxide (TiO 2 ) nanofiber catalyst synthesized by a simple electrospinning method could effectively convert N 2 into NH 3 at room temperature. The Ag-doped TiO 2 nanofibers had a high NH 3 yield rate of 3.158 × 10 –10 mol s –1 cm –2 with a Faradaic efficiency (FE) of 0.13% at a low overpotential of −0.6 V versus a reversible hydrogen electrode (RHE) in acidic solution (0.1 mol L –1 HCl). The absence of hydrazine in the system proved that the prepared catalyst has excellent selectivity. Operation for eight consecutive cycles at an overpotential of −0.6 V vs RHE demonstrated the high stability of the Ag-doped TiO 2 nanofibers without obvious variations in the NH 3 yield rate and FE. The current density in the chronoamperometric curve did not decrease remarkably over 12 h of continuous electrolysis, thus confirming the durability of the catalyst. This work proves that Ag/TiO 2 nanofibers may be a highly efficient ENRR catalyst that could achieve high NH 3 yield rates. The unique structure of the interface between Ag and TiO 2 in the Ag/TiO 2 nanofibers prepared by electrospinning not only enhances the adsorption of N 2 but also promotes electron exchange and the synergy between the nanofibers and N 2 .