Enhancing Green Ammonia Electrosynthesis through Bi–Mo Bimetallic Oxides on Two-Dimensional Ti3C2Tx MXene under Ambient Conditions

In this paper, Bi–Mo bimetallic oxides (Bi₂Mo₃O₁₂) were successfully grown on two-dimensional (2D) Ti₃C₂T_x MXene nanosheets by a hydrothermal reaction to form Bi₂Mo₃O₁₂@Ti₃C₂T_x composites and used for an electrocatalytic nitrogen reduction reaction. The experimental results show that in a 0.1 M Na₂SO₄ electrolyte the NH₃ yield rate of Bi₂Mo₃O₁₂@Ti₃C₂T_x reaches 78.52 μg^–1 mg^–1_cat. at −0.7 V vs RHE. This result is much higher than those of Bi₂Mo₃O₁₂ (23.45 μg h^–1 mg^–1_cat.) and Ti₃C₂T_x MXene (16.34 μg h^–1 mg^–1_cat.) alone. And the Faraday efficiency (FE) of Bi₂Mo₃O₁₂@Ti₃C₂T_x reaches the highest value of 49.38% at −0.55 V vs RHE (Bi₂Mo₃O₁₂, 12.16%; Ti₃C₂T_x MXene, 9.3%). Meanwhile, the ¹H NMR spectrum of ¹⁵N proves that the N of NH₃ in the experiment comes from the N₂ atmosphere passed during the experiment. Density functional theory (DFT) calculations indicate that the reduction pathway of N₂ on Bi₂Mo₃O₁₂@Ti₃C₂T_x is dominated by the distal pathway.