Electrochemical N2 fixation is considered to be a promising alternative to Haber-Bosch technology. Inspired by the composition and structure of natural nitrogenase, Fe-doped VS2 nanosheets were prepared via one-step solvothermal method. The electron transfer system mediated by organic conductive polymer (1-AAQ-PA) was constructed to promote the electron transfer between Fe-VS2 nanosheets and the electrode in electrocatalytic N2 reduction reaction (NRR). The obtained 1-AAQ-PA-Fe-VS2 electrode converted N2 to NH3 with a yield of 31.6 μg h-1 mg-1 at -0.35 V vs. reversible hydrogen electrode and high faradaic efficiency of 23.5 %. The introduction of Fe dopants favored N2 adsorption and activation, while the Li-S bond between Fe-VS2 and Li2 SO4 effectively inhibited hydrogen evolution. The highly efficient electron utilization in the electrocatalytic NRR process was realized using the 1-AAQ-PA as the electron transfer medium. Density functional theory calculations showed that N2 was preferentially adsorbed on Fe and reduced to NH3 via both distal and alternating mechanism.
Keywords: Fe doping; electrocatalysis; nanosheets; nitrogen reduction reaction; organic conductive polymers.
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