Highly Active Electrocatalysis of the Hydrogen Evolution Reaction by Cobalt Phosphide Nanoparticles

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.

Amorphous nickel-cobalt complexes hybridized with 1T-phase molybdenum disulfide via hydrazine-induced phase transformation for water splitting

“…4b), 2.5H-PHNCMs could afford a current density of 10 mA cm −2 with an overpotential of 235 mV and kept the activity for 24 h (Fig. 4d), which outstandingly ranked as the best among reported OER catalysts1617181920212223 and was much better than that of commercial IrO 2 /C catalyst. A performance comparison of PHNCMs for OER polarization (Supplementary Fig.…”

Facile Synthesis of M-MOF-74 (M=Co, Ni, Zn) and its Application as an ElectroCatalyst for Electrochemical CO2 Conversion and H2 Production

“…Given that the hydrogen evolution reaction (E o = 0.0 V RHE ) precedes the reduction of CO 2 (E o = -0.11 V RHE ), it is more probable that the initial current response was due to the hydrogen evolution. It is known that Co and Ni are efficient hydrogen evolution catalysts, and they have been intensively investigated [39][40][41]. Hence, the smaller overpotentials for Co-and Ni-MOF-74 compared to Zn-MOF-74 were ascribed to their superior catalytic activities toward hydrogen evolution.…”

Enhanced hydrogen evolution reaction on hybrids of cobalt phosphide and molybdenum phosphide

“…Very recently, metal phosphides have received great attention owing to their superior catalytic activity towards the HER which rivals platinum catalysts [10–12]. It has previously been reported by Schaak and co-workers [13–15] that orthorhombic CoP and Co 2 P nanocrystallines produced cathodic current density of 20 mA cm −2 at overpotentials ranging from 85 to 117 mV and stable over 24 h of operation. Bulk hexagonal molybdenum phosphide (MoP) has shown stable HER activity in acidic solution with overpotentials of 140–246 mV for driving a current density of 10 mA cm −2 [16,17].…”