Multiple synergies on cobalt-based spinel oxide nanowires for electrocatalytic oxygen evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Cobalt-based spinel oxides are promising oxygen evolution reaction (OER) catalysts.
• Poor electrical conductivity and stability limit their commercial use.
• Developing efficient and stable OER catalysts is crucial for energy technologies.

Purpose of the Study:

• To enhance the OER activity and stability of cobalt-nickel spinel oxides.
• To introduce oxygen vacancies and boron oxide motifs onto Co3-xNixO4 nanowires.
• To provide a facile method for designing advanced OER catalysts.

Main Methods:

• Modification of Co3-xNixO4 nanowires using sodium borohydride (NaBH4) treatment.
• Characterization using X-ray photoelectron spectroscopy (XPS) and in situ Raman spectroscopy.
• Electrochemical testing for oxygen evolution reaction (OER) performance evaluation.

Main Results:

• NaBH4 treatment introduced significant oxygen vacancy content and decorated BOx motifs.
• Enhanced conductivity, hydrophilicity, and increased active sites were observed.
• Optimized BOx-covered Co2.1Ni0.9O4 achieved 10 mA cm-2 at 307 mV overpotential and maintained stability at 50 mA cm-2 for 24 hours.

Conclusions:

• The facile modification method significantly boosts the OER performance of cobalt-based spinel oxides.
• Oxygen vacancies and BOx decoration are effective strategies for improving catalyst conductivity and active sites.
• This approach offers a promising pathway for developing highly efficient and stable OER catalysts for electrochemical applications.