Beyond Colloidal Synthesis: Nanofiber Reactor to Design Self-Supported Core–Shell Pd₁₆S₇/MoS₂/CNFs Electrode for Efficient and Durable Hydrogen Evolution Catalysis

Developing an efficient and stable hydrogen evolution catalyst is the core issue to promoting the wide application of hydrogen energy. Herein, we report a novel strategy to design a self-supported core–shell Pd₁₆S₇/MoS₂/CNFs electrode by the electrospinning technology and sulfur vapor-assisted chemical vapor deposition. The unique Pd₁₆S₇/MoS₂ core–shell structures with high content of unsaturated sulfur atoms were synthesized in situ in the carbon nanofiber (CNF) reactors. The formation of Pd–S–Mo nanointerfaces in Pd₁₆S₇/MoS₂ core/shell heterostructures can effectively regulate the electron orbital of MoS₂ and expose more sulfur vacancies, which were active sites for the hydrogen evolution reaction (HER). Beyond the colloidal synthesis, the self-supported Pd₁₆S₇/MoS₂/CNFs could be directly used as electrode materials, and the electrode with excellent hydrophobic properties can accelerate the bubble desorption during the reaction and improve hydrogen evolution stability. The Pd₁₆S₇/MoS₂/CNFs electrode affords a small overpotential of 83 mV at a geometric current density of 10 mA cm^–2 and Tafel slope of 113 mV dec^–1, suggesting a higher intrinsic activity (88 mV at 1 mA cm^–2_ECSA) and remarkable durability.