Loading the FeNiOOH cocatalyst on Pt-modified hematite nanostructures for efficient solar water oxidation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Hematite (Fe2O3) is a promising photoanode material for photoelectrochemical water splitting.
• Improving the efficiency and stability of hematite photoanodes remains a key challenge.
• Co-catalyst decoration is a common strategy to enhance photoanode performance.

Purpose of the Study:

• To develop a facile method for preparing FeNiOOH-decorated hematite photoanodes.
• To investigate the effect of FeNiOOH decoration on the photoelectrochemical performance of hematite.
• To understand the role of FeNiOOH as a co-catalyst for the oxygen evolution reaction.

Main Methods:

• Facile electrodeposition of FeNiOOH onto hematite photoanodes.
• Synchrotron radiation-based techniques (e.g., X-ray absorption spectroscopy) for compositional analysis.
• Photoelectrochemical measurements to evaluate performance (onset potential, photocurrent).

Main Results:

• FeNiOOH decoration resulted in a significant cathodic shift of the onset potential (up to 190 mV).
• Enhanced oxygen evolution reaction kinetics were observed with the FeNiOOH co-catalyst.
• The FeNiOOH-decorated hematite photoanode demonstrated excellent long-term stability.
• Coupling with a Pt-modified hematite photoanode achieved a high photocurrent of 2.21 mA cm(-2) at 1.23 V vs. RHE.

Conclusions:

• The electrodeposition of FeNiOOH is a facile and effective strategy to enhance hematite photoanode performance.
• FeNiOOH acts as an efficient co-catalyst, improving both activity and stability.
• This approach holds promise for developing efficient and durable photoelectrochemical water splitting systems.