Ultrathin Amorphous Nickel Doped Cobalt Phosphates with Highly Ordered Mesoporous Structures as Efficient...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for energy conversion technologies.
• Cobalt-based materials are promising OER catalysts, but their performance and stability need improvement.

Purpose of the Study:

• To report the facile preparation of ultrathin 2D cobalt phosphate (CoPi) nanoflakes.
• To investigate the effect of nickel doping on the OER performance of CoPi nanoflakes.
• To evaluate the potential of Ni-doped CoPi nanoflakes for energy conversion applications.

Main Methods:

• Synthesis of ultrathin 2D cobalt phosphate (CoPi) nanoflakes via an oil-phase method.
• Characterization of the nanoflakes' structure, including thickness, mesoporosity, and amorphous nature.
• Electrocatalytic testing for the oxygen evolution reaction (OER) in 1.0 m KOH solution.

Main Results:

• Successfully prepared ultrathin (≈3.8 nm) 2D mesoporous CoPi nanoflakes with an amorphous structure.
• Ni-doped CoPi nanoflakes exhibited enhanced intrinsic activity and a low kinetic barrier for OER.
• Optimized Ni10-CoPi demonstrated a low overpotential (320 mV at 10 mA cm⁻²) and small Tafel slope (44.5 mV dec⁻¹), comparable to RuO₂.
• Ni10-CoPi showed high stability for OER in alkaline solution.

Conclusions:

• The 2D mesoporous Ni-doped CoPi nanoflakes are effective electrocatalysts for the oxygen evolution reaction.
• The facile synthesis and excellent OER performance make Ni10-CoPi a promising material for energy conversion applications.
• This work provides a new avenue for designing advanced catalysts based on doped cobalt phosphates.