Sodium Cobalticarborane: A Promising Precatalyst for Oxygen Evolution Reaction.

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Water splitting converts renewable electricity into fuel, but the oxygen evolution reaction (OER) is a bottleneck.
• Efficient, low-cost, stable, and environmentally friendly OER catalysts are critical for practical water splitting.
• Current OER catalysts often face limitations in cost, stability, or efficiency.

Purpose of the Study:

• To introduce sodium cobalticarborane as a novel precatalyst for generating cobalt-based OER catalysts.
• To investigate the OER activity of the derived cobalt catalyst using various electrode materials.
• To evaluate the performance metrics such as overpotential and Tafel slope for the synthesized catalyst.

Main Methods:

• Synthesis of a cobalt-based catalyst from sodium cobalticarborane precatalyst.
• Characterization of the cobalt-based catalyst, identified as Co(III) (hydr)oxide.
• Electrochemical evaluation of OER activity using fluorine-doped tin oxide, glassy carbon, gold, and platinum electrodes in KOH solution.

Main Results:

• The cobalt-based catalyst derived from sodium cobalticarborane demonstrated OER activity across multiple electrode types.
• Onset overpotentials for OER varied by electrode: 315 mV (FTO), 275 mV (Au), 284 mV (Pt), and 330 mV (GC).
• Nanoparticles on gold electrodes showed significant activity (Tafel slope 63.8 mV/dec, 541 mV overpotential at 50 mA/cm²).

Conclusions:

• Sodium cobalticarborane is a viable precatalyst for synthesizing effective cobalt oxide OER catalysts.
• The synthesized catalyst exhibits promising OER performance, particularly on gold electrodes.
• This approach offers a new pathway for low-cost cobalt oxide catalyst preparation for water splitting applications.