Stable Solar Water Splitting Enabled in Anodic W/WO₃ Nanorod Based Electrodes by Hydrothermal Engineering.

Area of Science:

• Materials Science
• Electrochemistry
• Photocatalysis

Background:

• Tungsten oxide (WO3) photoelectrodes face stability challenges in neutral media, especially when made via anodic oxidation.
• Improving light absorption and charge separation is crucial for efficient solar water splitting.

Purpose of the Study:

• To develop a simple method to enhance the stability and performance of anodic WO3 photoelectrodes.
• To investigate the effects of a hydrothermal treatment on WO3 morphology and properties.

Main Methods:

• A one-step hydrothermal treatment was applied to porous anodic WO3.
• Characterization involved photoluminescence, photocurrent measurements, and electrochemical impedance spectroscopy.

Main Results:

• The treatment transformed WO3 into nanorods with a dispersed FeWO4 phase, improving light absorption and reducing charge recombination.
• Modified electrodes showed a ~1.8x higher photocurrent density at 1.0 V vs RHE due to enhanced charge separation and a p-n heterojunction.
• Oxygen vacancy formation contributed to stability and photocurrent stabilization over several hours.

Conclusions:

• The scalable surface engineering approach significantly enhances WO3 photoelectrode performance and durability.
• This method offers a promising route for practical solar-driven water oxidation applications.