A Highly Efficient Bi₂O₂Se/Bi₂WO₆ S-Scheme Heterojunction Photocatalyst for Solar Water Splitting: A First-Principles...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Two-dimensional (2D) S-scheme heterojunctions are crucial for solar energy conversion due to their redox capabilities.
• Efficient photocatalysts are needed for solar-driven hydrogen production.

Purpose of the Study:

• To design and investigate a 2D/2D S-scheme heterojunction of Bi₂O₂Se and Bi₂WO₆ for photocatalytic water splitting.
• To evaluate its performance in solar energy harvesting and hydrogen production.

Main Methods:

• First-principles calculations were employed to study the electronic band structures and charge separation mechanisms.
• Gibbs free energy calculations were used to assess the spontaneity of water splitting.
• Solar-to-hydrogen (STH) conversion efficiency was calculated.

Main Results:

• The Bi₂O₂Se/Bi₂WO₆ heterojunction exhibits well-aligned band structures and an intrinsic built-in electric field.
• An efficient S-scheme charge migration mechanism promotes effective charge separation and reduces carrier recombination.
• The heterojunction demonstrates spontaneous water splitting driven by solar energy.

Conclusions:

• The Bi₂O₂Se/Bi₂WO₆ S-scheme heterojunction is a highly promising photocatalyst for efficient solar-driven hydrogen production.
• Its excellent light-harvesting capability and charge migration contribute to a high STH conversion efficiency of 23.48%.
• This material offers a stable and effective solution for renewable hydrogen generation.