Delaminated two-dimensional Ti3C2Tx Mxene engineered gadolinium nitride nanostructures as an efficient bifunctional electrocatalyst for hydrogen and oxygen evolution reactions

Developing cost-effective and efficient bifunctional electrocatalysts is critical for sustainable hydrogen production via overall water splitting. Here, we report the rational design and synthesis of a gadolinium nitride-decorated Mxene (Gd-N/Ti 3 C 2 T x ) nanocomposite as a high-performance bifunctional electrocatalyst. The Gd-N/Ti 3 C 2 T x hybrid shows excellent activity toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under alkaline conditions. The optimized electrode exhibits low overpotentials of 315.2 mV for HER and 162.8 mV for OER at 10 mA cm −2 , with Tafel slopes of 142 and 234 mV dec −1 , respectively, indicating favorable kinetics. In a two-electrode alkaline water electrolyzer, Gd-N/Ti 3 C 2 T x achieves 10 mA cm −2 at a cell voltage of 1.74 V, outperforming individual Gd-N and Ti 3 C 2 T x electrodes. The system maintains stable operation at 10 mA cm −2 for 48 h with negligible voltage fluctuation. The enhanced performance arises from strong interfacial coupling between conductive Ti 3 C 2 T x layers and catalytically active Gd-N, which promotes rapid charge transfer, increases electrochemically active surface area, and facilitates reaction kinetics. This work demonstrates Gd-N/Ti 3 C 2 T x as an earth-abundant, durable, and efficient bifunctional electrocatalyst for overall water splitting.