A New Water-Soluble Copper(II) Coordination Polymer for Electrocatalytic Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient catalysts are crucial for green hydrogen production through water splitting electrolysis.
• Developing low-cost, earth-abundant electrocatalysts for the oxygen evolution reaction (OER) remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize a novel water-soluble copper-(II) coordination polymer for OER electrocatalysis.
• To investigate the catalytic activity, stability, and mechanism of the synthesized copper coordination polymer for OER.

Main Methods:

• Synthesis of a one-dimensional copper-(II) coordination polymer using a ligand inspired by photosystem II.
• Single-crystal X-ray diffraction for structural analysis.
• Electrocatalytic testing in phosphate buffer (pH 12.5) to evaluate OER performance.
• Kinetic studies and stability tests (chronopotentiometry, cyclic voltammetry).

Main Results:

• A novel water-soluble copper-(II) coordination polymer with a unique monatomic bridge structure was synthesized.
• The catalyst exhibited an onset overpotential of 394 mV at 0.1 mA cm^-2 for OER.
• Kinetic analysis indicated first-order electron transfer with a turnover frequency of 2.1 s^-1.
• Stability tests revealed the formation of a CuOx-OH film, suggesting a contribution from heterogeneous electrocatalysis.

Conclusions:

• The synthesized copper coordination polymer is a promising earth-abundant molecular electrocatalyst for the oxygen evolution reaction.
• The catalyst's performance is comparable to existing copper(II) molecular catalysts.
• The study highlights the potential of coordination polymers inspired by natural systems for efficient green hydrogen generation.