TiO₂-based photocatalysts from type-II to S-scheme heterojunction and their applications

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Photocatalysis offers a sustainable route for environmental remediation and solar energy utilization.
• Titanium dioxide (TiO2) is a widely studied photocatalyst due to its favorable properties, but suffers from limitations like charge recombination and poor solar light absorption.
• Heterojunction engineering of TiO2 is a key strategy to overcome these limitations by improving charge carrier separation and transfer.

Purpose of the Study:

• To review the progress and current status of TiO2 modification through heterojunction construction.
• To discuss advancements in understanding charge transfer mechanisms, from Type II to S-scheme.
• To highlight synthetic approaches, interface engineering, and applications of TiO2-based heterostructures.

Main Methods:

• Review of existing literature on TiO2 modification and heterojunctions.
• Analysis of different charge transfer mechanisms (Type II, S-scheme).
• Discussion of synthetic strategies and interface engineering techniques for TiO2 heterostructures.

Main Results:

• TiO2 heterojunctions significantly enhance photocatalytic performance by promoting charge carrier separation.
• Understanding of charge transfer dynamics has evolved, with S-scheme mechanisms offering new possibilities.
• Various TiO2 heterostructures (with metal oxides, sulfides, carbon nitride) demonstrate effectiveness in key applications.

Conclusions:

• TiO2-based heterojunctions are crucial for advancing photocatalysis, offering improved efficiency and selectivity.
• Key applications include hydrogen production, CO2 conversion, and organic pollutant degradation.
• Addressing sustainability, scalability, and commercialization challenges is vital for the future of TiO2 photocatalysis.