Systematic Constructing FeOCl/BiVO₄ Hetero-Interfacial Hybrid Photoanodes for Efficient Photoelectrochemical Water...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Bismuth vanadate (BiVO4) is a promising photoanode material for photoelectrochemical (PEC) water splitting.
• However, BiVO4 suffers from limitations in charge separation and light absorption efficiencies, hindering its practical application.
• Developing efficient cocatalysts is crucial to overcome these limitations and enhance PEC performance.

Purpose of the Study:

• To introduce iron oxychloride (FeOCl) as a novel cocatalyst for BiVO4 photoanodes.
• To investigate the effect of FeOCl on the photoelectrochemical water splitting performance of BiVO4.
• To elucidate the mechanisms behind the enhanced PEC activity through experimental and theoretical analyses.

Main Methods:

• Fabrication of FeOCl/BiVO4 heterostructure photoanodes.
• Photoelectrochemical measurements, including photocurrent density and incident photon-to-current efficiency (IPCE).
• Experimental characterization and density functional theory (DFT) calculations to understand charge transfer and catalytic mechanisms.

Main Results:

• The optimized FeOCl/BiVO4 photoanode achieved a high photocurrent density of 5.23 mA cm⁻² at 1.23 V vs RHE under AM 1.5G illumination.
• FeOCl grafting enhanced charge transport, light absorption, and water oxidation kinetics.
• DFT calculations confirmed that FeOCl optimizes intermediate Gibbs free energies, boosting catalytic activity.

Conclusions:

• Iron oxychloride (FeOCl) is an effective cocatalyst for improving BiVO4 photoanodes in PEC water splitting.
• The FeOCl/BiVO4 heterostructure demonstrates superior PEC performance due to synergistic effects.
• This study highlights FeOCl as a promising material for developing highly efficient photoanodes for solar fuel production.