Engineering Zeolitic-Imidazolate-Framework-Derived Mo-Doped Cobalt Phosphide for Efficient OER Catalysts

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient catalysts are essential for water splitting to produce oxygen.
• Existing catalysts often lack the required durability, cost-effectiveness, or competence.
• Metal-organic frameworks offer unique structural properties for catalyst design.

Purpose of the Study:

• To design a cost-effective and durable catalyst for the oxygen evolution reaction (OER).
• To synthesize molybdenum-doped cobalt phosphide (CoP) using ZIF-67 as a template and precursor.
• To investigate the effect of molybdenum doping on catalytic performance.

Main Methods:

• A two-step synthesis involving dissolution-regrowth of ZIF-67 with Na2MoO4, followed by phosphidation.
• Fabrication of molybdenum-doped cobalt phosphide (CoP) with a hollow nanocage morphology.
• Electrochemical testing to evaluate OER activity, including onset potential and Tafel slope.

Main Results:

• The synthesized catalyst exhibited a hollow nanocage structure, enhancing porosity and surface area.
• Molybdenum-doped CoP demonstrated excellent catalytic activity for OER with a low overpotential.
• The optimal catalyst (CoMoP-2) showed an onset potential of 1.49 V and a Tafel slope of 62.1 mV dec⁻¹.

Conclusions:

• The ZIF-67-originated, molybdenum-doped cobalt phosphide is a highly effective catalyst for the oxygen evolution reaction.
• The hollow nanocage morphology and increased surface area contribute to the enhanced catalytic performance.
• This catalyst presents a promising, cost-effective solution for oxygen generation via water splitting.