C18-thiol modified Fe-MoSe2 nanosheets for efficient electrocatalytic nitrogen fixation

Achieving high ammonia yield and Faraday efficiency is a long-sought-after goal in electrochemical N2 fixation. Yet, the competitive hydrogen evolution in nitrogen reduction process and the low local concentration of nitrogen on the working electrode still limited the electrocatalytic performance. In the present contribution, a Fe-MoSe2 nanosheet functioned with C18-thiol as a nano-hydrophobic surface was rationally constructed, which efficiently facilitated the three-phase contact of gas (N2), liquid (H2O electrolyte), and solid (electrocatalyst). The fabrication of modified hydrophobic surface not only overcame the mass transfer limitation of N2 and increased the local concentration of N2 molecules on the catalyst, but also reduced the proton contact with electrocatalyst to inhibit HER. The three-phase electrocatalytic system achieved a high NH3 yield of 34.75 μg h−1 mg−1 and outstanding Faraday efficiency of 23.31%. The adsorption and activation processes during NRR process were systematically investigated by the combination of experimental results and density function theory (DFT) simulations.