Co/WC@NC electrocatalysts derived from polyoxometalates (POM) for efficient hydrogen evolution.

The stable hydrogen generation catalysts with favorable performance have been widely studied. As we all know, bimetallic hybrids have been emerged as one type of outstanding electrocatalysts and applied to electrochemical hydrogen generation field. In this work, using bimetallic polyoxometalates (POM) as soft templates and polyethyleneimine (PEI) as carbon source, we synthesized cobalt and tungsten-based bimetallic electrocatalysts (Co/WC@NC) via one-step simple high temperature calcination process.Co/WC@NCexhibits good hydrogen evolution performances. Thereinto, the overpotentials are 129 and 142 mV at the current density of 10 mA cm-2, and the Tafel slopes are 93 and 91 mV dec-1in 0.5 M H2SO4and 1.0 M KOH aqueous solutions, respectively. Furthermore, the catalyst shows good stability for 24 h. The excellent catalytic performance (Co/WC@NC) can be ascribed to the synergistic effect of WC and Co nanoparticles and the protection function of graphitic carbon layers. Furthermore, this work may provide an experimental guidance for the large-scale production of low-cost materials with good catalytic effects.