Highly active electrocatalysis of the hydrogen evolution reaction by cobalt phosphide nanoparticles

Angew Chem Int Ed Engl. 2014 May 19;53(21):5427-30. doi: 10.1002/anie.201402646. Epub 2014 Apr 11.

Abstract

Nanoparticles of cobalt phosphide, CoP, have been prepared and evaluated as electrocatalysts for the hydrogen evolution reaction (HER) under strongly acidic conditions (0.50 M H2SO4, pH 0.3). Uniform, multi-faceted CoP nanoparticles were synthesized by reacting Co nanoparticles with trioctylphosphine. Electrodes comprised of CoP nanoparticles on a Ti support (2 mg cm(-2) mass loading) produced a cathodic current density of 20 mA cm(-2) at an overpotential of -85 mV. The CoP/Ti electrodes were stable over 24 h of sustained hydrogen production in 0.50 M H2SO4. The activity was essentially unchanged after 400 cyclic voltammetric sweeps, suggesting long-term viability under operating conditions. CoP is therefore amongst the most active, acid-stable, earth-abundant HER electrocatalysts reported to date.

Keywords: electrocatalysis; hydrogen evolution; metal phosphide; nanomaterials; water splitting.