Industrial-Si-based photoanode for highly efficient and stable water splitting

Area of Science:

• Materials Science
• Renewable Energy
• Electrochemistry

Background:

• Photoelectrochemical (PEC) water splitting offers sustainable solar energy harvesting but faces challenges in cost and efficiency.
• Industrial silicon (Indus-Si) is a promising material for photoelectrodes due to its abundance and established manufacturing processes.

Purpose of the Study:

• To develop a cost-effective and high-performance photoanode for PEC water splitting using industrial silicon.
• To investigate the structural and chemical modifications of a cobalt co-catalyst on an industrial silicon photoanode and their impact on performance.

Main Methods:

• Fabrication of an industrial-Si-based photoanode (n-Indus-Si/Co) via simple electrodeposition.
• Characterization using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS).
• Analysis of co-catalyst morphology, chemical states, and their influence on charge transfer and reaction kinetics.

Main Results:

• A uniform and adherent dispersion of cobalt co-catalyst particles was achieved, leading to a high built-in electric field.
• Electrodeposition and subsequent activation resulted in a core-shell structure of co-catalyst particles.
• Improved charge separation and transfer, reduced charge transfer resistance, and enhanced water oxidation kinetics were observed.

Conclusions:

• The engineered n-Indus-Si/Co photoanode demonstrates low cost, stability, and high performance for PEC water splitting.
• Surface reconstruction and chemical state modification of the co-catalyst are crucial for efficient charge dynamics.
• This work provides a pathway for industrial-scale solar energy conversion through advanced photoelectrode engineering.