Constructing Chainmail-Structured CoP/C Nanospheres as Highly Active Anodic Electrocatalysts for Oxygen Evolution...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Developing efficient, earth-abundant electrocatalysts is critical for the oxygen evolution reaction (OER).
• Noble metal catalysts like RuO2 are effective but expensive and scarce.
• There is a significant need for cost-effective and highly active alternatives for OER.

Purpose of the Study:

• To synthesize and characterize novel, noble metal-free electrocatalysts for the oxygen evolution reaction (OER).
• To investigate the catalytic performance and stability of carbon-coated cobalt phosphide (CoP/C) nanospheres.
• To elucidate the mechanism behind the enhanced activity of the developed catalyst.

Main Methods:

• A direct impregnation coupling phosphorization approach was employed to synthesize uniform carbon-coated CoP nanospheres (CoP/C).
• Electrochemical performance was evaluated using techniques such as cyclic voltammetry and chronoamperometry.
• In situ Raman spectroscopy was utilized to study the reaction intermediates and understand the catalytic mechanism.

Main Results:

• The synthesized CoP/C catalyst exhibited a low overpotential of 230 mV at 10 mA cm-2 and a Tafel slope of 56.87 mV dec-1.
• The intrinsic activity of CoP/C was found to be 21.44 times higher than commercial RuO2 at an overpotential of 260 mV.
• In situ Raman spectroscopy indicated that Co-O and Co-OH species facilitate *OH adsorption, accelerating reaction kinetics.
• The carbon shell enhanced the active surface area and protected CoP from oxidative dissolution, improving stability.

Conclusions:

• Uniform carbon-coated CoP nanospheres are highly active and stable electrocatalysts for the oxygen evolution reaction.
• The synergistic effect between CoP and the carbon shell contributes to the superior catalytic performance.
• This work offers a promising strategy for developing advanced, noble metal-free OER catalysts.