Heteroatom-doped titanium carbide MXene synthesized using mild etching route as an efficient bifunctional electrocatalyst for water splitting

Two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides (MXenes) are promising electrocatalysts due to their exceptional physicochemical properties. However, their application is limited by conventional synthesis methods using concentrated hydrofluoric acid (HF), posing serious safety concerns. Here, we report a safer, direct HF-free hydrothermal etching strategy for synthesizing high-quality Ti 3 C 2 T x MXene flakes. Structural and morphological analyses confirm successful etching, revealing a well-defined 2D structure with characteristic accordion-like morphology. The electrocatalytic performance of pristine and heteroatom-doped Ti 3 C 2 T x was evaluated for alkaline water splitting. The doped MXene showed superior activity, delivering over 125 mV lower overpotential at 10 mA cm −2 for HER, improved OER performance, and excellent bifunctional stability for 200 h. These improvements are attributed to the high surface area of exfoliated MXene flakes, intrinsic metallic conductivity, and the synergistic effects of heteroatom doping. This work establishes a scalable, sustainable MXene synthesis approach and clarifies structure-performance relationships for efficient hydrogen production.