Hydrophobicity Tailoring of Ferric Covalent Organic Framework/MXene Nanosheets for High‐Efficiency Nitrogen Electroreduction to Ammonia

Abstract Electrocatalytic nitrogen reduction reaction (NRR) represents a promising sustainable approach for NH 3 synthesis. However, the poor NRR performance of electrocatalysts is a great challenge at this stage, mainly owing to their low activity and the competitive hydrogen evolution reaction (HER). Herein, 2D ferric covalent organic framework/MXene (COF‐Fe/MXene) nanosheets with controllable hydrophobic behaviors are successfully prepared via a multiple‐in‐one synthetic strategy. The boosting hydrophobicity of COF‐Fe/MXene can effectively repel water molecules to inhibit the HER for enhanced NRR performances. By virtue of the ultrathin nanostructure, well‐defined single Fe sites, nitrogen enrichment effect, and high hydrophobicity, the 1H,1H,2H,2H‐perfluorodecanethiol modified COF‐Fe/MXene hybrid shows a NH 3 yield of 41.8 µg h −1 mg cat. −1 and a Faradaic efficiency of 43.1% at −0.5 V versus RHE in a 0.1 m Na 2 SO 4 water solution, which are vastly superior to the known Fe‐based catalysts and even to the noble metal catalysts. This work provides a universal strategy to design and synthesis of non‐precious metal electrocatalysts for high‐efficiency N 2 reduction to NH 3 .