Hf-Doped CoP Hollow Nanocubes as High-Performance Electrocatalyst for Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Designing hollow frame structures with 3D open architectures for electrocatalysis is challenging.
• Metal-organic frameworks (MOFs) can be synthesized into hollow structures via etching.
• Developing efficient and stable electrocatalysts is crucial for energy conversion technologies.

Purpose of the Study:

• To design and synthesize Hf-doped CoP hollow nanocubes for electrocatalysis.
• To investigate a novel selective etching method for creating unique MOF structures.
• To evaluate the catalytic performance of the synthesized material for the oxygen evolution reaction (OER).

Main Methods:

• Selective etching of ZIF-67 using acid xylenol orange solution to form bell-like structures (XO-ZIF-67).
• Hf4+ doping and phosphating treatment to synthesize Hf-doped CoP hollow nanocubes.
• Electrochemical testing to assess OER activity and stability.

Main Results:

• A unique bell-like MOF structure (XO-ZIF-67) was successfully synthesized via selective etching.
• Hf-doped CoP hollow nanocubes were obtained through subsequent doping and phosphating.
• The catalyst exhibited a low overpotential of 291 mV at 10 mA cm-2 for OER.
• Excellent stability was demonstrated in 1 M KOH solution for 25 hours.

Conclusions:

• The developed Hf-doped CoP hollow nanocubes are highly efficient and stable electrocatalysts for OER.
• Selective etching offers a promising route for synthesizing advanced hollow MOF structures.
• This work contributes to the development of novel materials for energy applications.