Synergistic performance of nitrogen and sulfur co-doped Ti3C2TX for electrohydrogenation of N2 to NH3

Abstract High-polluting industrial ammonia synthesis runs counter to the intentions of a low-carbon society. In contrast, the electrocatalytic nitrogen reduction reaction (NRR) is expected to provide fascinating and broad prospects for green ammonia synthesis, which urgently requires efficient and low-cost catalysts. Although it has been proven that two-dimensional (2D) transition metal carbides and carbonitrides (MXenes) have great potential for NRR, there is still need to further improve their activity. In this work, a co-doping strategy was employed to design the electronic configuration and structural mechanic of Ti3C2Tx catalysts for efficient NRR. As expected, the synergistic effect of N and S dopants in Ti3C2Tx (NS-Ti3C2Tx) significantly improves the electron/ion transport capacity and increases the catalytic active sites. Specifically, the as-prepared NS-Ti3C2Tx nanosheets demonstrated an excellent electrocatalytic stability with NH3 yield of 34.23 μg·h-1·mg-1cat at -0.55 V vs. RHE, and a Faraday efficiency of 6.6% in 0.05 M H2SO4. Therefore, this work opens up a new research approach for preparing high-performance catalysts for energy storage applications through efficient nitrogen fixation technology.