Self-supported V-doped NiO electrocatalyst achieving a high ammonia yield of 30.55 μg h−1 cm−2 under ambient conditions†
Abstract
To date, lots of efforts have been devoted to exploring an efficient route for N2 fixation under ambient conditions. However, due to the high bond energy of the strong NN triple bond, it is still restricted by low NH3 yield and conversion efficiency. Based on a previous concept of using carbohydrates as an accessory ingredient to form hollow metal oxides, here, we report V-doped NiO self-supported on nickel foam as an excellent NRR catalyst. Using glucose as a dispersant to disperse the surface of V-doped NiO, V/NiO with a disordered morphology reaches its highest NH3 yield rate of 30.55 μg h−1 cm−2 at −0.3 V vs. reversible hydrogen electrode (RHE) and achieves a high faradaic efficiency (FE) of 11% at −0.1 V vs. RHE in 0.1 M KOH. Compared to NiO (5.32 μg h−1 cm−2), V/NiO shows significantly improved NRR performance. Further, using 15N2 as a supply gas gives strong evidence for the accurate detection of the generated NH3 of V/NiO and N2-TPD shows that V/NiO has stronger binding strength towards N2, resulting in a splendid NH3 yield rate.