Enhanced Catalytic Activity in Nitrogen-Anion Modified Metallic Cobalt Disulfide Porous Nanowire Arrays for Hydrogen Evolution

Rational design of cost-effective and non-precious-metal electrocatalysts for the hydrogen evolution reaction (HER) still remains a great challenge for future applications in sustainable energy storage and conversion systems. In this work, we developed a simple nitrogen-anion decoration strategy to realize the synergistic regulation of the catalytically active sites, electronic structure, and reaction dynamics in metallic CoS2 porous nanowire (NW) arrays. Specifically, the introduction of nitrogen anion in the CoS2 system, revealed by the XPS and XANES spectra, not only modified the morphology, offering additional active sites, but also enhanced the electrical conductivity to promote rapid charge transfer for the HER process. Synergistically, density functional theory confirms that the N incorporation results in more optimal free energy of hydrogen adsorption for either S or Co active sites, benefiting the HER kinetics. As expected, the N-CoS2 NW/carbon cloth (CC) electrode showed significantly enhanced HER performance with a lower overpotential and a larger exchange current density than the pristine one. This work provides a promising idea to the rational design of advanced and highly efficient electrocatalysts for hydrogen production.