Mixed-valent cobalt phosphate/borophene nanohybrids for efficient electrocatalytic oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient, low-cost, non-precious, and stable electrocatalysts is crucial for sustainable electrocatalytic water splitting.
• Borophene, a novel 2D material, shows theoretical promise for electrocatalysis, but practical applications are limited.
• Cobalt phosphate is a known electrocatalyst, but its efficiency and stability can be further improved.

Purpose of the Study:

• To synthesize and investigate the electrocatalytic activity of a mixed-valent cobalt phosphate/borophene nanohybrid (BCoPi) for the oxygen evolution reaction (OER).
• To explore the role of borophene in enhancing catalytic activity and stability.
• To compare the performance of BCoPi with pristine cobalt phosphate.

Main Methods:

• Hydrothermal synthesis of the mixed-valent cobalt phosphate/borophene nanohybrid (BCoPi).
• Systematic electrochemical studies to evaluate OER activity in an alkaline medium.
• Analysis of kinetic parameters, including Tafel slope, to understand reaction mechanisms.

Main Results:

• The BCoPi nanohybrid demonstrated superior OER performance compared to pristine cobalt phosphate.
• Achieved current densities of 50, 100, and 500 mA cm⁻² at lower overpotentials (337, 357, and 401 mV, respectively).
• Exhibited a low Tafel slope of 61.81 mV dec⁻¹, indicating faster OER kinetics and excellent long-term stability.

Conclusions:

• The electron-deficient and conductive nature of borophene enhances catalytic site activation and electron transport.
• BCoPi acts as a proton acceptor and provides multiple active sites, overcoming OER scaling relations.
• This study highlights the potential of borophene-based heterostructures as highly active and stable electrocatalysts for various applications.