Preparation of Ti₃C₂T_xMXene-based copper/cobalt composites for electrocatalytic ammonia synthesis

MXenes represent exceptionally promising electrocatalytic materials for ammonia synthesis, owing to their outstanding electrical conductivity, modifiable surface functional groups, exceptional hydrophilicity, high specific surface area, and electronegative surface characteristics. In this investigation, we systematically demonstrate that the persistent challenge of Cu and Co nanoparticle agglomeration can be effectively addressed through the in-situ growth of bimetallic CuCo nanoparticles on Ti₃C₂T_xMXene nanosheets. This innovative approach significantly enlarges the electrochemically active surface area, maximizes the exposure of catalytically active sites, and optimizes mass transport properties, consequently leading to substantially enhanced electrocatalytic performance for ammonia synthesis. Among the series of Cu_xCo_y/MXene composites developed, the Cu₂Co₁/MXene hybrid catalyst demonstrates superior nitrate reduction reaction (NO₃RR) activity, achieving remarkable performance metrics including: An exceptional ammonia yield rate of 2.73 mg cm^-2 h^-1 at an applied potential of -0.85 V versus RHE, a high Faradaic efficiency of 72.05 %, and outstanding selectivity reaching 90.6 %. These breakthrough results establish new benchmarks for MXene-based electrocatalysts in sustainable ammonia production.