Sana Akir, Bastian Schmiedecke, Debabrata Bagchi, Jan Plutnar, Prashanth W. Menezes, Yael Rodriguez‐Ayllon, Yan Lü, Zdeněk Sofer, Michelle P. Browne
Designing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for advancing sustainable energy technologies. In this study, a 2D/2D heterostructure composed of 1T-phase molybdenum disulfide (1T-MoS 2 ) and titanium carbide MXene (Ti 3 C 2 T x, denoted as Ti 3 C 2 ) is synthesized using a one-step hydrothermal method. The hybrid catalyst exhibits improved HER kinetics, demonstrated by a low overpotential of 248 mV at 10 mA cm −2 and a Tafel slope of 55 mV dec −1 , indicating fast reaction kinetics and favorable charge transfer. The addition of tetramethylammonium ions (TMA + ) induces interlayer expansion, increasing the 1T phase content to 89%. Incorporating only 1% Ti 3 C 2 MXene suppresses oxidation and enhances stability. The composite demonstrates a large electrochemical surface area, high turnover frequency (TOF), and retains over 90% of its catalytic activity after extended electrolysis. This scalable approach offers a promising route to developing stable, efficient 2D electrocatalysts for hydrogen production.