A [Co₁₉(OH)₁₂]²⁶⁺-Incorporating Polyoxotungstate for Electrocatalytic Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Transition-metal oxides are crucial for oxygen evolution reaction (OER) catalysis.
• Cobalt-containing polyoxometalates (POMs) show significant promise as OER catalysts.

Purpose of the Study:

• To synthesize and explore a new [Co19(OH)12]-unit-incorporating polyoxotungstate (CoSiW) for highly efficient OER.
• To investigate the structural features and electrocatalytic performance of the synthesized CoSiW.

Main Methods:

• Synthesis of Na34[Co19(OH)12(α-SiW10O37)6]·46H2O (CoSiW).
• Electrochemical characterization of CoSiW for OER in 0.1 M KOH.
• Comparison of CoSiW performance against other cobalt-containing POMs and cobalt oxide.

Main Results:

• CoSiW exhibits an overpotential of 329.4 mV at 10 mA·cm−2 and a low Tafel slope of 80.8 mV·dec−1.
• The catalyst demonstrates high stability, operating for over 40 hours at 60.0 mA·cm−2.
• The unique sandwich-type structure with hydroxyl bridges and cooperative Co-O-Co interactions enhances catalytic activity.

Conclusions:

• The novel CoSiW polyoxotungstate is a highly efficient and stable electrocatalyst for OER.
• Its unique structural features, including hydroxyl bridges and multiple active sites, are key to its enhanced performance.
• CoSiW presents a cost-effective electrocatalyst with potential for renewable energy applications.