Direct Z-Scheme Cs₂O-Bi₂O₃-ZnO Heterostructures as Efficient Sunlight-Driven Photocatalysts

Area of Science:

• Materials Science
• Environmental Science
• Photocatalysis

Background:

• Photocatalytic water treatment faces challenges including limited light absorption and inefficient charge separation.
• Developing advanced materials is crucial for effective pollutant degradation.

Purpose of the Study:

• To synthesize direct Z-scheme Cs2O-Bi2O3-ZnO heterostructures for enhanced photocatalytic water treatment.
• To investigate the role of Cs2O in improving light absorption and charge carrier separation.

Main Methods:

• Facile, fast, and economic solution combustion synthesis of Cs2O-Bi2O3-ZnO heterostructures.
• Photocatalytic degradation of 4-chlorophenol under simulated sunlight.
• Characterization using UV-vis diffuse reflectance spectroscopy, electrochemical impedance, and transient photocurrent measurements.
• Radical-trapping experiments to verify the Z-scheme mechanism.

Main Results:

• The synthesized Cs2O-Bi2O3-ZnO heterostructures exhibit extended light absorption into visible and near-infrared regions.
• The material demonstrates efficient electron-hole separation attributed to the Z-scheme mechanism facilitated by Cs2O.
• Successful degradation of 4-chlorophenol was achieved, indicating high photocatalytic activity.

Conclusions:

• The direct Z-scheme Cs2O-Bi2O3-ZnO heterostructures are effective for photocatalytic water treatment.
• The presence of Cs2O is key to enhancing light absorption and promoting efficient charge separation via a Z-scheme pathway.
• This approach offers a promising strategy for developing high-performance photocatalysts for environmental remediation.