Hierarchical NbS₂/MoS₂-Carbon Nanofiber Electrode for Highly Efficient and Stable Hydrogen Evolution Reaction at All Ranges of pH

There is an urgent need to develop efficient and nonprecious electrode materials for practical electrocatalyst hydrogen evolution reaction (HER) application to restrain the depletion of fossil fuels. In the present work, we report an efficient and cost-effective electrode with high stability for binder-free water electrolysis under all ranges of pH from 0 to 14. Herein, a two-dimensional (2D) heterostructure of NbS2/MoS2 ultrathin vertical nanosheets was grown on carbon nanofiber with a high aspect ratio by the one-step chemical vapor deposition approach. The resultant hybrid catalyst demonstrates superlative HER performance with a small onset potential (41 mV @ ∼0 pH, 22 mV @ ∼7 pH and 32 mV @ ∼14 pH) and a very low overpotential (0.23 V @ ∼0 pH, 0.21 V @ ∼7 pH and 0.33 V @ ∼14 pH to reach 50 mA/cm2) vs reversible hydrogen electrode (RHE). Besides, the fabricated NbS2/MoS2-CNF displays excellent chronoamperometry stability for more than 50 h in all pH ranges. The proposed heterostructure holds the vital prerequisites for being a significant electrode material owing to multiple HER active edge and planar sulfur sites, excellent barrier-free charge transfer ability toward the electrolyte, and impressive endurance. Overall, the 2D/one-dimensional (1D) hybrid heterostructure appeared to be a precious-metal-free flexible electrode for excellent HER performance under wide ranges of pH for water splitting applications.