A Facile Design for Water-Oxidation Molecular Catalysts Precise Assembling on Photoanodes

Area of Science:

• Materials Science
• Electrochemistry
• Photocatalysis

Background:

• Efficient photoelectrochemical water oxidation is crucial for renewable energy technologies.
• Interfacial charge transfer between cocatalysts and semiconductors is a key bottleneck.

Purpose of the Study:

• To engineer an effective charge transfer pathway for improved photoelectrochemical water oxidation.
• To utilize bismuth vanadate (BiVO4) photoanodes with a novel cocatalyst arrangement.

Main Methods:

• Fabrication of a bismuth vanadate (BiVO4) photoanode.
• Immobilization of cyano-functionalized cobalt cubane (Co4O4) molecules on an gold (Au) binding bridge.
• Characterization of the photoanode's structure and electrochemical performance.

Main Results:

• Achieved a photocurrent density of 5.06 mA cm⁻² at 1.23 V vs. RHE, a 3.4-fold increase over BiVO4.
• Demonstrated suppressed surface charge recombination with over 95% charge transfer efficiency.
• Established an ordered charge transfer pathway from BiVO4 to Co4O4 via the Au bridge.

Conclusions:

• The Au binding bridge effectively facilitates hole transfer from BiVO4 to Co4O4.
• This orchestrated arrangement significantly enhances photoelectrochemical water oxidation efficiency.
• The strategy offers a promising route for developing advanced photoelectrocatalysts.