Boosting oxygen evolution reaction rates with mesoporous Fe-doped MoCo-phosphide nanosheets

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Transition metal catalysts are crucial for efficient water electrolysis and hydrogen production.
• The oxygen evolution reaction (OER) is a key bottleneck in water electrolysis, requiring highly efficient catalysts.
• Developing catalysts with abundant active sites and defects is essential for enhancing OER performance.

Purpose of the Study:

• To synthesize and characterize novel MoCoFe-phosphide catalyst nanosheets for improved OER activity.
• To investigate the structural and electronic properties influencing the catalyst's electrochemical performance.
• To evaluate the catalyst's efficiency and stability for hydrogen fuel production.

Main Methods:

• One-step hydrothermal reaction and chemical vapor deposition-based phosphorization for catalyst synthesis.
• Electrochemical characterization, including overpotential and Tafel slope measurements.
• X-ray photoelectron spectroscopy (XPS) for surface analysis and electronic structure determination.

Main Results:

• MoCoFe-phosphide nanosheets exhibited excellent electrical conductivity and a high density of active sites.
• Achieved a low OER overpotential of 250 mV at 10 mA cm^-2 and a Tafel slope of 43.38 mV dec^-1.
• Demonstrated superior catalytic activity and stability in alkaline media, attributed to modulated electronic properties and abundant defects.

Conclusions:

• The MoCoFe-phosphide catalyst offers a promising pathway for cost-effective hydrogen fuel production.
• Synergistic effects of Mo and Fe doping enhance the OER performance of CoP-based catalysts.
• The catalyst's high activity is linked to abundant defects, Co²⁺ sites, and favorable interfacial charge transfer.