Water Adsorption and Dissociation Promoted by Co*-/N-C*-Biactive Sites of Metallic Co/N-Doped Carbon Hybrids for Efficient Hydrogen Evolution

Combining theoretical and experimental studies is one of the most optimistic strategies to synthesize highperformance electrocatalysts for water splitting. Herein Co nanoparticles (NPs)/N-doped carbon (Co/N-C) hybrid electrocatalysts with biactive sites, hierarchical porosity and high specific surface area were successfully designed and fabricated. The detail mechanism of hydrogen evolution through Co*-/N-C*-biactive sites was demonstrated by DFT calculations and was further confirmed via in situ Raman spectra. The coupled effects between the Co NPs and N-doped carbon of Co/N-C hybrids can facilitate water adsorption, activation and dissociation, and the Co/N-C hybrid electrocatalysts exhibit the superior catalytic activity with a low overpotential of only similar to 84 mV at 10 mA/cm(2) and excellent stability for hydrogen evolution in alkaline media. This study will provide an insight into the biactive sites nature in the Co/N-C hybrids and will offer a new strategy for the design of high-performance electrocatalysts.