Unveiling Morphology-Structure Interplay on Hydrothermal WO₃ Nanoplatelets for Photoelectrochemical Solar Water...

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Photoelectrochemical (PEC) water splitting is a sustainable method for hydrogen production.
• Tungsten trioxide (WO3) is a promising semiconductor material for photoanodes.
• Optimizing WO3 synthesis is crucial for enhancing PEC efficiency.

Purpose of the Study:

• To develop a seed layer-free hydrothermal synthesis for WO3 photoanodes.
• To optimize synthesis parameters (temperature, time, layer thickness) for improved PEC water splitting.
• To investigate the influence of morphological and structural properties on WO3 photoanode performance.

Main Methods:

• Seed layer-free hydrothermal synthesis of WO3 nanoplatelets.
• Systematic variation of synthesis temperature, time, and multilayer deposition.
• Characterization of morphological, structural, and optical properties (XRD, SEM).
• PEC performance evaluation using photocurrent measurements.
• Adaptation of Mott-Schottky equation to include fractal dimension.

Main Results:

• A low-temperature (90 °C, 12 h) and multilayer strategy significantly enhanced photocurrent.
• The five-layer WO3 photoanode showed over a 70% increase in photocurrent compared to a single layer.
• Fractal dimension and (220) crystalline orientation were identified as key factors influencing PEC response.
• Rietveld refinement revealed the importance of crystallographic facets, unit cell expansion, and microstrain.

Conclusions:

• Optimized synthesis parameters and multilayer deposition are critical for high-efficiency WO3 photoanodes.
• Nanoplatelet morphology and structural characteristics are intrinsically linked to PEC performance.
• The study provides insights into tailoring WO3 nanostructures for advanced hydrogen production.