Substitution Boosts Charge Separation for High Solar-Driven Photocatalytic Performance

Area of Science:

• Materials Science
• Photocatalysis
• Solid-State Chemistry

Background:

• Bandgap engineering is crucial for optimizing photocatalyst solar resource utilization.
• Simultaneously achieving narrow bandgaps and high activity is challenging with traditional methods.

Purpose of the Study:

• To overcome limitations in traditional photocatalyst modification.
• To investigate the effects of iodine-bromine substitution in BiOBr on photocatalytic properties.

Main Methods:

• Synthesized BiOBr$_{0.75}$I$_{0.25}$ via substitution of iodine for bromine in BiOBr.
• Evaluated photocatalytic activity and photon-to-current conversion efficiency.
• Analyzed bandgap, electron diffusion, and defect structures.

Main Results:

• BiOBr$_{0.75}$I$_{0.25}$ demonstrated significantly enhanced photoactivity compared to TiO$_{2}$, BiOBr, and BiOI.
• Substitution narrowed the bandgap and improved electron diffusion.
• Induced oxygen vacancies and enhanced intrinsic electric fields within the material.

Conclusions:

• Iodine substitution in BiOBr is an effective strategy for developing high-efficiency photocatalysts.
• The enhanced properties stem from bandgap narrowing, improved charge carrier dynamics, and defect engineering.
• This work offers insights into hybrid-halide photocatalysts for solar energy applications.