Carbon nitride-based Z-scheme heterojunctions for solar-driven advanced oxidation processes

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Solar-driven advanced oxidation processes (AOPs) are effective for wastewater remediation.
• Artificial Z-scheme materials offer enhanced photocatalytic activity due to separated charge carriers and strong redox capabilities.
• Graphitic carbon nitride (g-C3N4, CN) is a promising metal-free material for Z-scheme photocatalyst development.

Purpose of the Study:

• To summarize the development of CN-based direct and indirect Z-scheme photocatalysts for solar-driven AOPs.
• To examine engineering strategies for enhancing CN-based Z-scheme photocatalysts.
• To discuss the rational design of indirect CN-based Z-scheme systems.

Main Methods:

• Classification of AOPs and definition/validation of Z-schemes.
• Examination of engineering strategies including morphology control, doping, defect engineering, cocatalyst loading, and tandem Z-scheme construction for direct Z-schemes.
• Discussion of charge mediators (solid conductive materials, soluble ion pairs) for indirect Z-scheme systems.

Main Results:

• CN-based materials show potential as metal-free Z-scheme photocatalysts for solar AOPs.
• Various engineering strategies can significantly improve the performance of CN-based direct Z-schemes.
• Rational design of indirect Z-scheme systems using appropriate charge mediators enhances catalytic activity.

Conclusions:

• CN-based Z-scheme photocatalysts are a promising avenue for efficient solar-driven wastewater remediation.
• Understanding the structure-activity relationship is crucial for optimizing CN-based Z-schemes.
• Future research should address limitations and challenges to advance this field.