Fe-VS2 Electrocatalyst with Organic Matrix-Mediated Electron Transfer for Highly Efficient Nitrogen Fixation

Graphical Nitrogen reduction : A bionic nitrogen fixation system composed of Fe-VS 2 nanosheets and 1-aminoanthraquinone-functionalized polymethacrylic acid (1-AAQ-PA) matrix is fabricated with 1-AAQ-PA as the electron medium to achieved high NH 3 yield rate of 31.6 μg h −1 mg −1 and faradaic efficiency to NH 3 of 23.1 % in 0.05 m Li 2 SO 4 electrolyte at −0.35 V vs. reversible hydrogen electrode. This work provides inspiration and insights for the development of effective catalyst systems for nitrogen reduction. Electrochemical N 2 fixation is considered to be a promising alternative to Haber–Bosch technology. Inspired by the composition and structure of natural nitrogenase, Fe-doped VS 2 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-VS 2 nanosheets and the electrode in electrocatalytic N 2 reduction reaction (NRR). The obtained 1-AAQ-PA−Fe-VS 2 electrode converted N 2 to NH 3 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 N 2 adsorption and activation, while the Li−S bond between Fe-VS 2 and Li 2 SO 4 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 N 2 was preferentially adsorbed on Fe and reduced to NH 3 via both distal and alternating mechanism.