Rational Design of Hydroxyl‐Rich Ti3C2Tx MXene Quantum Dots for High‐Performance Electrochemical N2 Reduction

Abstract To enable an efficient and cost‐effective electrocatalytic N 2 reduction reaction (NRR) the development of an electrocatalyst with a high NH 3 yield and good selectivity is required. In this work, Ti 3 C 2 T x MXene‐derived quantum dots (Ti 3 C 2 T x QDs) with abundant active sites enable the development of efficient NRR electrocatalysts. Given surface functional groups play a key role on the electrocatalytic performance, density functional theory calculations are first conducted, clarifying that hydroxyl groups on Ti 3 C 2 T x offer excellent NRR activity. Accordingly, hydroxyl‐rich Ti 3 C 2 T x QDs (Ti 3 C 2 OH QDs) are synthesized as NRR catalysts by alkalization and intercalation. This material offers an NH 3 yield and Faradaic efficiency of 62.94 µg h −1 mg −1 cat. and 13.30% at −0.50 V, respectively, remarkably higher than reported MXene catalysts. This work demonstrates that MXene catalysts can be mediated through the optimization of both QDs sizes and functional groups for efficient ammonia production at room temperature.