CdS-doped Ti3C2Tx MXene for efficient and stable electrocatalytic hydrogen evolution reaction

The global demand for clean energy has intensified the search for efficient, earth-abundant electrocatalysts for the hydrogen evolution reaction (HER). Herein, a series of CdS-doped Ti 3 C 2 T x MXene nanocomposites (MC1-MC4, containing 0.5-5 wt% CdS) were successfully synthesized via a facile hydrothermal approach and comprehensively evaluated for electrocatalytic HER performance in 0.5 M H 2 SO 4 electrolyte. Structural characterization by XRD confirmed the doping of CdS to the layered MXene structure, while Raman spectroscopy revealed systematic phonon shifts consistent with compressive in-plane strain, with 1 wt% CdS identified as the optimal interfacial loading. TEM analysis confirmed the anchoring of CdS nanoparticles onto Ti 3 C 2 T x nanosheets. Among all samples, MC2 (1 wt% CdS doped MXene) demonstrated the most outstanding HER activity, exhibiting the lowest overpotential of 310 mV at -10 mA/cm − 2 , the smallest Tafel slope of 98 mV/dec, the lowest charge transfer resistance (R ct = 152.2 Ω), the highest mass activity of 48.90 A/g, and the largest ECSA of 38.625 cm 2 . Furthermore, MC2 exhibited exceptional long-term stability over 2000 LSV cycles with a negligible overpotential shift of 9.21 mV. These results establish CdS-doped Ti 3 C 2 T X MXene as a promising, cost-effective electrocatalyst for sustainable hydrogen production.