Heterostructured CoP·CoMoP nanocages as advanced electrocatalysts for efficient hydrogen evolution over a wide pH...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical water splitting is a sustainable method for high-purity hydrogen production.
• Commercialization is hindered by the lack of cost-effective electrocatalysts for the hydrogen evolution reaction (HER) across a wide pH range.
• Transition metal phosphides (TMPs) are emerging as promising noble-metal-free HER electrocatalysts.

Purpose of the Study:

• To synthesize and characterize novel CoP·xCoMoP heterostructured nanocages (NCs) as efficient and pH-universal HER electrocatalysts.
• To evaluate the catalytic performance and stability of these TMPs for electrochemical water splitting.

Main Methods:

• Synthesis of CoP·xCoMoP NCs using metal-organic frameworks (MOFs) as templates via dissolution-regrowth and phosphorization.
• Characterization of the 3D heterostructured nanocage architecture composed of CoP and CoMoP phases.
• Electrochemical evaluation of HER activity and stability in various pH electrolytes (alkaline, acidic, and neutral buffered solutions).

Main Results:

• The optimal CoP·5CoMoP NC catalyst exhibited excellent HER activity, delivering 10 mA cm⁻² at low overpotentials (72 mV in KOH, 44 mV in H₂SO₄, 151 mV in PBS).
• The catalyst demonstrated a pH-universal activity comparable to or exceeding many reported noble-metal-free HER electrocatalysts.
• CoP·5CoMoP NCs showed remarkable long-term stability in HER over a wide pH range without significant performance degradation.

Conclusions:

• The developed 3D CoP·xCoMoP heterostructured nanocages are efficient, low-cost, and stable electrocatalysts for HER.
• These catalysts hold significant promise for practical applications in water splitting devices, addressing the need for affordable and effective hydrogen production.
• The study highlights the potential of earth-abundant TMPs in advancing sustainable energy technologies.