Iron Oxide Photoanode for Glycerol-Assisted Hydrogen Production at 8.87 mA cm^-2

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Iron oxide (α-Fe2O3) is a promising photoanode material for photoelectrochemical water splitting due to its low cost, suitable band gap, and stability.
• However, its widespread application is hindered by inefficient charge transport and slow water oxidation kinetics.

Purpose of the Study:

• To develop a Ge and Ti co-doped Fe2O3 photoanode to overcome the limitations of pure iron oxide.
• To couple glycerol oxidation with cathodic hydrogen evolution for enhanced photoelectrochemical performance.
• To investigate the selective oxidation of glycerol to value-added products.

Main Methods:

• Fabrication of Ge and Ti co-doped α-Fe2O3 photoanodes.
• Photoelectrochemical measurements under simulated one-sun illumination (100 mW cm-2).
• Electrochemical analyses and density functional theory (DFT) calculations.

Main Results:

• The co-doped photoanode achieved a photocurrent density of 8.87 mA cm-2 at 1.23 V vs. RHE in 1.0 M NaOH with 2.0 M glycerol, exceeding the benchmark of 8.1 mA cm-2.
• Ge incorporation facilitated selective oxidation of glycerol to tartronic acid.
• DFT calculations and electrochemical analyses indicated improved charge utilization and a promoted tartronic acid pathway.

Conclusions:

• Ge and Ti co-doping significantly enhances the photoelectrochemical performance of Fe2O3 for water splitting and glycerol oxidation.
• The developed photoanode offers a sustainable route for producing hydrogen and value-added chemicals.
• This work demonstrates a strategy for improving semiconductor photoanodes through targeted doping.