Efficient hydrogen production on MoNi<sub>4</sub> electrocatalysts with fast water dissociation kinetics.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28513620.
- Also identified by DOI 10.1038/ncomms15437 and PMC identifier 5442356.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Various platinum-free electrocatalysts have been explored for hydrogen evolution reaction in acidic solutions. However, in economical water-alkali electrolysers, sluggish water dissociation kinetics (Volmer step) on platinum-free electrocatalysts results in poor hydrogen-production activities. Here we report a MoNi<sub>4</sub> electrocatalyst supported by MoO<sub>2</sub> cuboids on nickel foam (MoNi<sub>4</sub>/MoO<sub>2</sub>@Ni), which is constructed by controlling the outward diffusion of nickel atoms on annealing precursor NiMoO<sub>4</sub> cuboids on nickel foam. Experimental and theoretical results confirm that a rapid Tafel-step-decided hydrogen evolution proceeds on MoNi<sub>4</sub> electrocatalyst. As a result, the MoNi<sub>4</sub> electrocatalyst exhibits zero onset overpotential, an overpotential of 15 mV at 10 mA cm<sup>-2</sup> and a low Tafel slope of 30 mV per decade in 1 M potassium hydroxide electrolyte, which are comparable to the results for platinum and superior to those for state-of-the-art platinum-free electrocatalysts. Benefiting from its scalable preparation and stability, the MoNi<sub>4</sub> electrocatalyst is promising for practical water-alkali electrolysers.