Coaxial Electrospun Hollow Carbon Nanofiber In Situ-Grown MoS2/CoS2 with Sulfur Vacancies for Enhanced Hydrogen Evolution Reaction

The development of cost-effective and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) is pivotal for sustainable hydrogen energy production. Herein, coaxial electrospinning one-dimensional (1D) hollow carbon nanofiber (HCNF) in situ-grown MoS2/CoS2 nanosheets were impregnated with a NaBH4 solution to obtain a HCNF-loaded sulfur-vacancy-rich MoS2/CoS2 heterojunction nanosheets catalyst of Vs-MoS2/CoS2-0.1@HCNFs. The unique hollow architecture afforded by electrospinning facilitates rapid electron transport and effectively mitigates the agglomeration of active 2D nanosheets, ensuring maximum exposure of catalytic sites. Furthermore, NaBH4 impregnation introduces abundant sulfur vacancies into the heterojunction lattice, synergistically modulating the electronic structure. Benefiting from the structural advantages of the electrospun framework and defect engineering, the optimized catalyst (Vs-MoS2/CoS2-0.1@HCNFs) exhibits superior HER activity in 1.0 M KOH, requiring an overpotential of only 115 mV to achieve a current density of 10 mA cm−2, along with a low Tafel slope of 83.3 mV dec−1 and excellent long-term stability. This study demonstrates the efficacy of electrospinning in designing high-performance, self-supported electrocatalysts for sustainable energy applications.